Grow journal: time-stamped notes on gardens, beds and plantings (#52) (#65)

Co-authored-by: Steve Dudenhoeffer <[email protected]>

DESIGN.md

@@ -23,6 +23,7 @@ SQLite, centimeters everywhere (display-side imperial conversion only), `version
 - **garden_objects** — one polymorphic table: `kind` (`bed`|`grow_bag`|`container`|`in_ground`|`tree`|`path`|`structure`), name, `shape` (`rect`|`circle`; `polygon` + `points` JSON reserved in schema, not in the v1 editor), center `x_cm`,`y_cm` in garden space, `width_cm`,`height_cm` (circle: width=diameter), `rotation_deg`, `z_index`, `plantable` bool, nullable `color` override, `props` JSON for kind-specific extras (bed height, tree species…), notes.
 - **seed_lots** — one purchase: vendor, source URL, sku, lot code, purchase date, packed-for year, quantity + unit, cost, germination %. `owner_id` is on the LOT, not inherited from the plant, so you can record buying generic built-in Garlic from Johnny's and keep it private. `plantings.seed_lot_id` (ON DELETE SET NULL) attributes a plop to a purchase; **`remaining` is derived** (quantity − summed effective count of active plantings), never stored — a decremented column drifts the moment a planting is edited behind its back and can't be audited afterwards. Lots are never shared along with a garden.
 - **plants** — catalog, plus `source_url`/`vendor` provenance for the variety itself. `owner_id NULL` = built-in (~30 seeded via migration, read-only, clone to customize). name, category (`vegetable`|`herb`|`flower`|`fruit`|`tree_shrub`|`cover`), `spacing_cm` (mature spacing), `color` hex, `icon` (emoji string — zero assets in v1), nullable `days_to_maturity`, notes. Users see built-ins + their own.
+- **journal_entries** — the grow log: `garden_id` (NOT NULL), nullable `object_id`/`planting_id` to narrow the target, author, body, `observed_at`. `notes` on a garden/object/plant says what the thing IS and a new note overwrites the old; a journal entry says what HAPPENED and when, and entries accumulate. `garden_id` is set even for a bed- or plop-level entry so permission checks reuse `requireGardenRole` unchanged rather than inventing a second ACL path. `observed_at` is distinct from `created_at` — you write up Saturday's observations on Sunday. Deliberately **not** in the revision history: entries are already append-shaped and individually versioned.
 - **change_sets** / **revisions** — the undo substrate. A change set groups the row-level revisions one logical operation produced (`source` ui/agent/api, `summary`, nullable `agent_run_id`, nullable `reverts_id`); a revision is `(entity_type, entity_id, op, before, after)` with full JSON row snapshots. The unit of undo is the **operation, not the row**. Revert is itself a change set, so an undo can be undone; it is version-guarded per entity and reports conflicts rather than clobbering a later edit. Garden *deletion* is deliberately not revertible (the cascade is invisible to the service, and would take the history with it).
 - **plantings** ("plops") — object_id, plant_id, center `x_cm`,`y_cm` **in the parent object's local frame** (moving/rotating a bed moves its plants for free), `radius_cm` (a plop is a circular patch), nullable `count` (NULL = derived: `max(1, round(π·r² / spacing_cm²))`), nullable label, `planted_at`/`removed_at` dates. "Clear bed" sets `removed_at`; v1 shows rows where `removed_at IS NULL`. Year-over-year history and a future plan/scenario layer build on these dates without schema surgery.
 

internal/api/api.go

@@ -85,6 +85,10 @@ func New(cfg *config.Config, svc *service.Service) *gin.Engine {
 	gardens.GET("/:id/full", h.getGardenFull)       // one-shot editor load
 	gardens.GET("/:id/history", h.getGardenHistory) // change sets, newest first
 	gardens.POST("/:id/objects", h.createObject)
+	// The grow journal hangs off a garden even for entries about one bed or one
+	// plop, so it inherits the ordinary garden-role check.
+	gardens.GET("/:id/journal", h.listJournal)
+	gardens.POST("/:id/journal", h.createJournalEntry)
 
 	// Sharing (owner-managed; a recipient may remove their own share).
 	gardens.GET("/:id/shares", h.listShares)
@@ -117,6 +121,12 @@ func New(cfg *config.Config, svc *service.Service) *gin.Engine {
 	changeSets := v1.Group("/change-sets", h.requireAuth())
 	changeSets.POST("/:id/revert", h.revertChangeSet)
 
+	// Journal entries are addressed by their own id; the service resolves the
+	// owning garden for the permission check, same as objects and plantings.
+	journal := v1.Group("/journal", h.requireAuth())
+	journal.PATCH("/:id", h.updateJournalEntry)
+	journal.DELETE("/:id", h.deleteJournalEntry)
+
 	// Plant catalog: built-ins (seeded, read-only) plus the actor's own rows.
 	plants := v1.Group("/plants", h.requireAuth())
 	plants.GET("", h.listPlants)

internal/api/journal.go

@@ -0,0 +1,142 @@
+package api
+
+import (
+	"errors"
+	"net/http"
+	"strconv"
+
+	"github.com/gin-gonic/gin"
+
+	"gitea.stevedudenhoeffer.com/steve/pansy/internal/domain"
+	"gitea.stevedudenhoeffer.com/steve/pansy/internal/service"
+)
+
+// Grow journal (#52). Entries hang off a garden even when they're about one bed
+// or one plop, which is what lets the permission check be the ordinary garden
+// role check with nothing new invented.
+
+// journalResponse is the body of GET /gardens/:id/journal.
+type journalResponse struct {
+	Entries []domain.JournalEntry `json:"entries"`
+	HasMore bool                  `json:"hasMore"`
+}
+
+// journalCreateRequest is the body for POST /gardens/:id/journal. observedAt
+// defaults to today when omitted — the common case is writing about now.
+type journalCreateRequest struct {
+	ObjectID   *int64  `json:"objectId"`
+	PlantingID *int64  `json:"plantingId"`
+	Body       string  `json:"body" binding:"required"`
+	ObservedAt *string `json:"observedAt"`
+}
+
+// journalUpdateRequest is the body for PATCH /journal/:id. Only the text and the
+// date it describes are editable; an entry's target and author are fixed.
+type journalUpdateRequest struct {
+	Body       *string `json:"body"`
+	ObservedAt *string `json:"observedAt"`
+	Version    int64   `json:"version" binding:"required"`
+}
+
+func (h *handlers) listJournal(c *gin.Context) {
+	gardenID, ok := parseIDParam(c, "id")
+	if !ok {
+		return
+	}
+	q := service.JournalQuery{
+		Limit:  intQuery(c, "limit", 0),
+		Offset: intQuery(c, "offset", 0),
+	}
+	var err error
+	if q.ObjectID, err = optionalIDQuery(c, "objectId"); err != nil {
+		writeAPIError(c, http.StatusBadRequest, "INVALID_INPUT", "invalid objectId")
+		return
+	}
+	if q.PlantingID, err = optionalIDQuery(c, "plantingId"); err != nil {
+		writeAPIError(c, http.StatusBadRequest, "INVALID_INPUT", "invalid plantingId")
+		return
+	}
+	if from := c.Query("from"); from != "" {
+		q.From = &from
+	}
+	if to := c.Query("to"); to != "" {
+		q.To = &to
+	}
+
+	entries, hasMore, err := h.svc.ListJournal(c.Request.Context(), mustActor(c).ID, gardenID, q)
+	if err != nil {
+		writeServiceError(c, err)
+		return
+	}
+	c.JSON(http.StatusOK, journalResponse{Entries: entries, HasMore: hasMore})
+}
+
+func (h *handlers) createJournalEntry(c *gin.Context) {
+	gardenID, ok := parseIDParam(c, "id")
+	if !ok {
+		return
+	}
+	var req journalCreateRequest
+	if err := c.ShouldBindJSON(&req); err != nil {
+		writeAPIError(c, http.StatusBadRequest, "INVALID_INPUT", "invalid entry: a body is required")
+		return
+	}
+	e, err := h.svc.CreateJournalEntry(c.Request.Context(), mustActor(c).ID, gardenID, service.JournalInput{
+		ObjectID: req.ObjectID, PlantingID: req.PlantingID, Body: req.Body, ObservedAt: req.ObservedAt,
+	})
+	if err != nil {
+		writeServiceError(c, err)
+		return
+	}
+	c.JSON(http.StatusCreated, e)
+}
+
+func (h *handlers) updateJournalEntry(c *gin.Context) {
+	id, ok := parseIDParam(c, "id")
+	if !ok {
+		return
+	}
+	var req journalUpdateRequest
+	if err := c.ShouldBindJSON(&req); err != nil {
+		writeAPIError(c, http.StatusBadRequest, "INVALID_INPUT", "invalid update: a current version is required")
+		return
+	}
+	e, err := h.svc.UpdateJournalEntry(c.Request.Context(), mustActor(c).ID, id,
+		service.JournalPatch{Body: req.Body, ObservedAt: req.ObservedAt}, req.Version)
+	if err != nil {
+		if errors.Is(err, domain.ErrVersionConflict) {
+			writeVersionConflict(c, e)
+			return
+		}
+		writeServiceError(c, err)
+		return
+	}
+	c.JSON(http.StatusOK, e)
+}
+
+func (h *handlers) deleteJournalEntry(c *gin.Context) {
+	id, ok := parseIDParam(c, "id")
+	if !ok {
+		return
+	}
+	if err := h.svc.DeleteJournalEntry(c.Request.Context(), mustActor(c).ID, id); err != nil {
+		writeServiceError(c, err)
+		return
+	}
+	c.Status(http.StatusNoContent)
+}
+
+// optionalIDQuery reads a positive int64 query parameter, or nil when absent.
+// A present-but-malformed value is an error rather than a silent nil, so a typo
+// doesn't quietly widen a filter to the whole garden.
+func optionalIDQuery(c *gin.Context, name string) (*int64, error) {
+	raw := c.Query(name)
+	if raw == "" {
+		return nil, nil
+	}
+	id, err := strconv.ParseInt(raw, 10, 64)
+	if err != nil || id < 1 {
+		return nil, errors.New("invalid id")
+	}
+	return &id, nil
+}

internal/api/journal_test.go

@@ -0,0 +1,157 @@
+package api
+
+import (
+	"net/http"
+	"strconv"
+	"testing"
+)
+
+func journalPath(gardenID int64) string {
+	return "/api/v1/gardens/" + strconv.FormatInt(gardenID, 10) + "/journal"
+}
+
+func journalEntryPath(id int64) string {
+	return "/api/v1/journal/" + strconv.FormatInt(id, 10)
+}
+
+// TestJournalCrudAPI walks the whole entry lifecycle over HTTP.
+//
+// It exists because the service-level tests could not see that PATCH and DELETE
+// were never registered on the router: the handlers were written, tested through
+// the service, and completely unreachable. Anything addressed by its own id
+// needs at least one test that goes through the router.
+func TestJournalCrudAPI(t *testing.T) {
+	r := authEngine(t, localCfg())
+	cookie := registerAndCookie(t, r, "[email protected]")
+	gid := createGardenAPI(t, r, cookie, "G")
+
+	w := doJSON(t, r, http.MethodPost, journalPath(gid), map[string]any{
+		"body": "First frost tonight", "observedAt": "2026-10-12",
+	}, cookie)
+	if w.Code != http.StatusCreated {
+		t.Fatalf("create: status %d, body %s", w.Code, w.Body.String())
+	}
+	entry := decodeMap(t, w.Body.Bytes())
+	id := int64(entry["id"].(float64))
+	if entry["observedAt"] != "2026-10-12" || entry["body"] != "First frost tonight" {
+		t.Errorf("unexpected entry: %+v", entry)
+	}
+
+	// List it back.
+	w = doJSON(t, r, http.MethodGet, journalPath(gid), nil, cookie)
+	if w.Code != http.StatusOK {
+		t.Fatalf("list: status %d, body %s", w.Code, w.Body.String())
+	}
+	body := decodeMap(t, w.Body.Bytes())
+	entries, _ := body["entries"].([]any)
+	if len(entries) != 1 {
+		t.Fatalf("got %d entries, want 1: %s", len(entries), w.Body.String())
+	}
+	if first := entries[0].(map[string]any); first["authorName"] == "" {
+		t.Error("author name missing from the list read")
+	}
+
+	// PATCH — the route this test exists for.
+	w = doJSON(t, r, http.MethodPatch, journalEntryPath(id), map[string]any{
+		"body": "First frost, tomatoes done", "version": entry["version"],
+	}, cookie)
+	if w.Code != http.StatusOK {
+		t.Fatalf("patch: status %d, body %s", w.Code, w.Body.String())
+	}
+	updated := decodeMap(t, w.Body.Bytes())
+	if updated["body"] != "First frost, tomatoes done" {
+		t.Errorf("body = %v", updated["body"])
+	}
+
+	// A stale version conflicts, carrying the current row.
+	w = doJSON(t, r, http.MethodPatch, journalEntryPath(id), map[string]any{
+		"body": "stale", "version": entry["version"],
+	}, cookie)
+	if w.Code != http.StatusConflict {
+		t.Errorf("stale patch: status %d, want 409", w.Code)
+	}
+	if current, _ := decodeMap(t, w.Body.Bytes())["current"].(map[string]any); current == nil {
+		t.Error("409 should carry the current row")
+	}
+
+	// DELETE — likewise.
+	w = doJSON(t, r, http.MethodDelete, journalEntryPath(id), nil, cookie)
+	if w.Code != http.StatusNoContent {
+		t.Fatalf("delete: status %d, body %s", w.Code, w.Body.String())
+	}
+	w = doJSON(t, r, http.MethodGet, journalPath(gid), nil, cookie)
+	if entries, _ := decodeMap(t, w.Body.Bytes())["entries"].([]any); len(entries) != 0 {
+		t.Errorf("%d entries survived the delete", len(entries))
+	}
+}
+
+// TestJournalFiltersAPI covers the query parameters, including a malformed one.
+func TestJournalFiltersAPI(t *testing.T) {
+	r := authEngine(t, localCfg())
+	cookie := registerAndCookie(t, r, "[email protected]")
+	gid := createGardenAPI(t, r, cookie, "G")
+
+	w := doJSON(t, r, http.MethodPost, objectsPath(gid), map[string]any{
+		"kind": "bed", "name": "North Bed", "xCm": 100, "yCm": 100, "widthCm": 100, "heightCm": 100,
+	}, cookie)
+	objectID := int64(decodeMap(t, w.Body.Bytes())["id"].(float64))
+
+	doJSON(t, r, http.MethodPost, journalPath(gid), map[string]any{
+		"body": "garden level", "observedAt": "2026-05-01",
+	}, cookie)
+	doJSON(t, r, http.MethodPost, journalPath(gid), map[string]any{
+		"objectId": objectID, "body": "bed level", "observedAt": "2026-06-01",
+	}, cookie)
+
+	countAt := func(query string) int {
+		t.Helper()
+		w := doJSON(t, r, http.MethodGet, journalPath(gid)+query, nil, cookie)
+		if w.Code != http.StatusOK {
+			t.Fatalf("list%s: status %d, body %s", query, w.Code, w.Body.String())
+		}
+		entries, _ := decodeMap(t, w.Body.Bytes())["entries"].([]any)
+		return len(entries)
+	}
+	if n := countAt(""); n != 2 {
+		t.Errorf("unfiltered = %d, want 2", n)
+	}
+	if n := countAt("?objectId=" + strconv.FormatInt(objectID, 10)); n != 1 {
+		t.Errorf("by object = %d, want 1", n)
+	}
+	if n := countAt("?from=2026-05-15&to=2026-12-31"); n != 1 {
+		t.Errorf("by date range = %d, want 1", n)
+	}
+
+	// A malformed filter is an error, not a silently ignored one that widens the
+	// query back to the whole garden.
+	w = doJSON(t, r, http.MethodGet, journalPath(gid)+"?objectId=abc", nil, cookie)
+	if w.Code != http.StatusBadRequest {
+		t.Errorf("malformed objectId: status %d, want 400", w.Code)
+	}
+	w = doJSON(t, r, http.MethodGet, journalPath(gid)+"?from=nonsense", nil, cookie)
+	if w.Code != http.StatusBadRequest {
+		t.Errorf("malformed from: status %d, want 400", w.Code)
+	}
+}
+
+// TestJournalRequiresAccessAPI — anonymous is 401, a stranger is 404.
+func TestJournalRequiresAccessAPI(t *testing.T) {
+	r := authEngine(t, localCfg())
+	owner := registerAndCookie(t, r, "[email protected]")
+	gid := createGardenAPI(t, r, owner, "G")
+	stranger := registerAndCookie(t, r, "[email protected]")
+
+	if w := doJSON(t, r, http.MethodGet, journalPath(gid), nil, nil); w.Code != http.StatusUnauthorized {
+		t.Errorf("anonymous list: status %d, want 401", w.Code)
+	}
+	if w := doJSON(t, r, http.MethodGet, journalPath(gid), nil, stranger); w.Code != http.StatusNotFound {
+		t.Errorf("stranger list: status %d, want 404", w.Code)
+	}
+	w := doJSON(t, r, http.MethodPost, journalPath(gid), map[string]any{"body": "nope"}, stranger)
+	if w.Code != http.StatusNotFound {
+		t.Errorf("stranger write: status %d, want 404", w.Code)
+	}
+	if w := doJSON(t, r, http.MethodDelete, journalEntryPath(1), nil, stranger); w.Code != http.StatusNotFound {
+		t.Errorf("stranger delete: status %d, want 404", w.Code)
+	}
+}

internal/domain/domain.go

@@ -165,6 +165,32 @@ type Revision struct {
 	After       *string `json:"after,omitempty"`
 }
 
+// JournalEntry is one time-stamped observation: what happened, and when.
+// Distinct from the mutable `notes` on a garden/object/plant, which says what
+// the thing IS — writing a new note overwrites the old one, while entries
+// accumulate.
+//
+// GardenID is set even when the entry is about a bed or a plop, so permission
+// checks reuse the garden role machinery unchanged; ObjectID/PlantingID narrow
+// the target without inventing a second ACL path.
+type JournalEntry struct {
+	ID         int64  `json:"id"`
+	GardenID   int64  `json:"gardenId"`
+	ObjectID   *int64 `json:"objectId,omitempty"`
+	PlantingID *int64 `json:"plantingId,omitempty"`
+	AuthorID   int64  `json:"authorId"`
+	Body       string `json:"body"`
+	// ObservedAt is when it happened ('YYYY-MM-DD'), which is not when it was
+	// written down: you write up Saturday's observations on Sunday.
+	ObservedAt string `json:"observedAt"`
+	Version    int64  `json:"version"`
+	CreatedAt  string `json:"createdAt"`
+	UpdatedAt  string `json:"updatedAt"`
+
+	// AuthorName is resolved for display by the service, never persisted.
+	AuthorName string `json:"authorName,omitempty"`
+}
+
 // RevertConflict reports one entity a revert deliberately left alone, because
 // reverting it would have discarded a change made after the change set being
 // reverted. The rest of the change set still reverts.

internal/service/journal.go

@@ -0,0 +1,239 @@
+package service
+
+import (
+	"context"
+	"errors"
+	"strings"
+
+	"gitea.stevedudenhoeffer.com/steve/pansy/internal/domain"
+	"gitea.stevedudenhoeffer.com/steve/pansy/internal/store"
+)
+
+// The grow journal (#52): what happened, and when. Distinct from the mutable
+// `notes` on a garden/object/plant, which says what the thing IS — a new note
+// overwrites the old one, while entries accumulate across a season.
+//
+// Deliberately NOT wired into the revision history (#48). Entries are already
+// append-shaped and individually versioned, and undoing a note is just deleting
+// it; running them through change sets would add a layer that buys nothing.
+
+const (
+	maxJournalBodyLen      = 10_000
+	maxJournalPageSize     = 200
+	defaultJournalPageSize = 50
+)
+
+// JournalInput is the payload for writing an entry. ObjectID/PlantingID are
+// optional and narrow the target; ObservedAt defaults to today.
+type JournalInput struct {
+	ObjectID   *int64
+	PlantingID *int64
+	Body       string
+	ObservedAt *string
+}
+
+// JournalPatch is a partial update. Only the text and the date it describes are
+// editable — see UpdateJournalEntry.
+type JournalPatch struct {
+	Body       *string
+	ObservedAt *string
+}
+
+// JournalQuery narrows a garden's journal for reading.
+type JournalQuery struct {
+	ObjectID   *int64
+	PlantingID *int64
+	From       *string
+	To         *string
+	Limit      int
+	Offset     int
+}
+
+// ListJournal returns a garden's entries, most recently observed first, for an
+// actor who can at least view the garden.
+func (s *Service) ListJournal(ctx context.Context, actorID, gardenID int64, q JournalQuery) ([]domain.JournalEntry, bool, error) {
+	if _, err := s.requireGardenRole(ctx, actorID, gardenID, roleViewer); err != nil {
+		return nil, false, err
+	}
+	if !validDatePtr(q.From) || !validDatePtr(q.To) {
+		return nil, false, domain.ErrInvalidInput
+	}
+	limit := q.Limit
+	if limit <= 0 {
+		limit = defaultJournalPageSize
+	}
+	if limit > maxJournalPageSize {
+		limit = maxJournalPageSize
+	}
+	offset := q.Offset
+	if offset < 0 {
+		offset = 0
+	}
+	// One row past the page answers hasMore without a second COUNT (same shape as
+	// GardenHistory).
+	entries, err := s.store.ListJournalEntries(ctx, gardenID, store.JournalFilter{
+		ObjectID: q.ObjectID, PlantingID: q.PlantingID, From: q.From, To: q.To,
+		Limit: limit + 1, Offset: offset,
+	})
+	if err != nil {
+		return nil, false, err
+	}
+	if len(entries) > limit {
+		return entries[:limit], true, nil
+	}
+	return entries, false, nil
+}
+
+// CreateJournalEntry writes an entry against a garden the actor can edit.
+//
+// An entry may target the garden, one of its beds, or one plop in it — and the
+// target is checked to actually belong to this garden. Without that, a valid
+// object id from someone else's garden would be accepted and then leak through
+// the list read, since the garden anchors the permission check.
+func (s *Service) CreateJournalEntry(ctx context.Context, actorID, gardenID int64, in JournalInput) (*domain.JournalEntry, error) {
+	if _, err := s.requireGardenRole(ctx, actorID, gardenID, roleEditor); err != nil {
+		return nil, err
+	}
+	objectID, err := s.resolveJournalTarget(ctx, gardenID, in.ObjectID, in.PlantingID)
+	if err != nil {
+		return nil, err
+	}
+
+	e := &domain.JournalEntry{
+		GardenID:   gardenID,
+		ObjectID:   objectID,
+		PlantingID: in.PlantingID,
+		AuthorID:   actorID,
+		Body:       strings.TrimSpace(in.Body),
+	}
+	if in.ObservedAt != nil {
+		e.ObservedAt = *in.ObservedAt
+	} else {
+		e.ObservedAt = s.now().UTC().Format(dateLayout)
+	}
+	if err := finalizeJournalEntry(e); err != nil {
+		return nil, err
+	}
+	return s.store.CreateJournalEntry(ctx, e)
+}
+
+// resolveJournalTarget validates an entry's target and returns the object id to
+// store against it.
+//
+// A plop-level entry gets its parent object filled in even when the caller
+// didn't name one. Without that, "notes about this bed" would silently exclude
+// every note written about a plant IN the bed — the bed filter and the plop
+// filter would disagree about what an entry is about, which is exactly the
+// question the reader is asking.
+//
+// A store failure that isn't "no such row" is passed through rather than
+// flattened to ErrInvalidInput: a database problem is not the caller's bad
+// request, and mapping it to a 400 would hide it from the logs entirely.
+func (s *Service) resolveJournalTarget(ctx context.Context, gardenID int64, objectID, plantingID *int64) (*int64, error) {
+	if objectID != nil {
+		o, err := s.store.GetObject(ctx, *objectID)
+		if errors.Is(err, domain.ErrNotFound) {
+			return nil, domain.ErrInvalidInput
+		}
+		if err != nil {
+			return nil, err
+		}
+		if o.GardenID != gardenID {
+			return nil, domain.ErrInvalidInput
+		}
+	}
+	if plantingID == nil {
+		return objectID, nil
+	}
+
+	pl, err := s.store.GetPlanting(ctx, *plantingID)
+	if errors.Is(err, domain.ErrNotFound) {
+		return nil, domain.ErrInvalidInput
+	}
+	if err != nil {
+		return nil, err
+	}
+	o, err := s.store.GetObject(ctx, pl.ObjectID)
+	if errors.Is(err, domain.ErrNotFound) {
+		return nil, domain.ErrInvalidInput
+	}
+	if err != nil {
+		return nil, err
+	}
+	if o.GardenID != gardenID {
+		return nil, domain.ErrInvalidInput
+	}
+	// A plop-level entry that ALSO names an object must name the right one.
+	if objectID != nil && *objectID != pl.ObjectID {
+		return nil, domain.ErrInvalidInput
+	}
+	return &pl.ObjectID, nil
+}
+
+// journalEntryForWrite loads an entry and enforces who may change it: the author
+// may edit their own, and the garden's OWNER may delete any — the same shape as
+// sharing, where the owner is the backstop for content in their garden. A
+// non-editor of the garden can't reach it at all, and an entry in a garden the
+// actor can't see is ErrNotFound (existence masked, as everywhere else).
+func (s *Service) journalEntryForWrite(ctx context.Context, actorID, entryID int64, ownerMayAct bool) (*domain.JournalEntry, error) {
+	e, err := s.store.GetJournalEntry(ctx, entryID)
+	if err != nil {
+		return nil, err // ErrNotFound
+	}
+	g, err := s.requireGardenRole(ctx, actorID, e.GardenID, roleEditor)
+	if err != nil {
+		return nil, err
+	}
+	if e.AuthorID == actorID {
+		return e, nil
+	}
+	if ownerMayAct && g.OwnerID == actorID {
+		return e, nil
+	}
+	// Visible (they can edit this garden) but not theirs to change.
+	return nil, domain.ErrForbidden
+}
+
+// UpdateJournalEntry edits the text or the observed date of the actor's OWN
+// entry. Deliberately author-only, including for the garden owner: rewriting
+// somebody else's observation under their name is a different thing from
+// removing it.
+func (s *Service) UpdateJournalEntry(ctx context.Context, actorID, entryID int64, patch JournalPatch, version int64) (*domain.JournalEntry, error) {
+	e, err := s.journalEntryForWrite(ctx, actorID, entryID, false)
+	if err != nil {
+		return nil, err
+	}
+	if patch.Body != nil {
+		e.Body = strings.TrimSpace(*patch.Body)
+	}
+	if patch.ObservedAt != nil {
+		e.ObservedAt = *patch.ObservedAt
+	}
+	if err := finalizeJournalEntry(e); err != nil {
+		return nil, err
+	}
+	e.Version = version
+	return s.store.UpdateJournalEntry(ctx, e)
+}
+
+// DeleteJournalEntry removes an entry. The author may delete their own; the
+// garden's owner may delete any entry in their garden.
+func (s *Service) DeleteJournalEntry(ctx context.Context, actorID, entryID int64) error {
+	e, err := s.journalEntryForWrite(ctx, actorID, entryID, true)
+	if err != nil {
+		return err
+	}
+	return s.store.DeleteJournalEntry(ctx, e.ID)
+}
+
+// finalizeJournalEntry validates a built/merged entry. Shared by create and
+// update so both enforce the same invariants.
+func finalizeJournalEntry(e *domain.JournalEntry) error {
+	if e.Body == "" || len(e.Body) > maxJournalBodyLen {
+		return domain.ErrInvalidInput
+	}
+	if !validDatePtr(&e.ObservedAt) {
+		return domain.ErrInvalidInput
+	}
+	return nil
+}

internal/service/journal_test.go

@@ -0,0 +1,325 @@
+package service
+
+import (
+	"context"
+	"errors"
+	"testing"
+
+	"gitea.stevedudenhoeffer.com/steve/pansy/internal/domain"
+)
+
+func writeEntry(t *testing.T, s *Service, actor, gardenID int64, in JournalInput) *domain.JournalEntry {
+	t.Helper()
+	e, err := s.CreateJournalEntry(context.Background(), actor, gardenID, in)
+	if err != nil {
+		t.Fatalf("CreateJournalEntry: %v", err)
+	}
+	return e
+}
+
+func listJournal(t *testing.T, s *Service, actor, gardenID int64, q JournalQuery) []domain.JournalEntry {
+	t.Helper()
+	entries, _, err := s.ListJournal(context.Background(), actor, gardenID, q)
+	if err != nil {
+		t.Fatalf("ListJournal: %v", err)
+	}
+	return entries
+}
+
+// TestEntriesAttachToGardenBedOrPlanting — the three targets, each listing under
+// itself and under the garden that anchors it.
+func TestEntriesAttachToGardenBedOrPlanting(t *testing.T) {
+	s := newTestService(t, openConfig())
+	owner := seedUser(t, s, "[email protected]")
+	g := seedGarden(t, s, owner)
+	bed := seedBed(t, s, owner, g.ID)
+	plant := seedOwnPlant(t, s, owner, 15)
+	ctx := context.Background()
+
+	plop, err := s.CreatePlanting(ctx, owner, bed.ID, PlantingInput{
+		PlantID: plant.ID, XCM: 0, YCM: 0, RadiusCM: 20,
+	})
+	if err != nil {
+		t.Fatalf("CreatePlanting: %v", err)
+	}
+
+	gardenEntry := writeEntry(t, s, owner, g.ID, JournalInput{Body: "First frost tonight"})
+	bedEntry := writeEntry(t, s, owner, g.ID, JournalInput{ObjectID: &bed.ID, Body: "Powdery mildew on the west bed"})
+	plopEntry := writeEntry(t, s, owner, g.ID, JournalInput{
+		ObjectID: &bed.ID, PlantingID: &plop.ID, Body: "Scapes forming",
+	})
+
+	// The garden sees all three: it anchors every entry.
+	if all := listJournal(t, s, owner, g.ID, JournalQuery{}); len(all) != 3 {
+		t.Errorf("garden journal has %d entries, want 3", len(all))
+	}
+	byBed := listJournal(t, s, owner, g.ID, JournalQuery{ObjectID: &bed.ID})
+	if len(byBed) != 2 {
+		t.Errorf("bed journal has %d entries, want 2 (the bed's and the plop's)", len(byBed))
+	}
+	byPlop := listJournal(t, s, owner, g.ID, JournalQuery{PlantingID: &plop.ID})
+	if len(byPlop) != 1 || byPlop[0].ID != plopEntry.ID {
+		t.Errorf("plop journal = %+v, want just the plop entry", byPlop)
+	}
+	if gardenEntry.ObjectID != nil || bedEntry.PlantingID != nil {
+		t.Error("targets leaked between entries")
+	}
+	if gardenEntry.AuthorID != owner {
+		t.Error("author not recorded")
+	}
+	// The author's name is resolved for display without a lookup per row.
+	if all := listJournal(t, s, owner, g.ID, JournalQuery{}); all[0].AuthorName == "" {
+		t.Error("author name not resolved on the list read")
+	}
+}
+
+// TestDeletingABedRemovesItsEntriesOnly — the cascade is scoped: losing a bed
+// must not take the garden's own season notes with it.
+func TestDeletingABedRemovesItsEntriesOnly(t *testing.T) {
+	s := newTestService(t, openConfig())
+	owner := seedUser(t, s, "[email protected]")
+	g := seedGarden(t, s, owner)
+	bed := seedBed(t, s, owner, g.ID)
+	ctx := context.Background()
+
+	writeEntry(t, s, owner, g.ID, JournalInput{Body: "Garden-level note"})
+	writeEntry(t, s, owner, g.ID, JournalInput{ObjectID: &bed.ID, Body: "Bed-level note"})
+
+	if err := s.DeleteObject(ctx, owner, bed.ID); err != nil {
+		t.Fatalf("DeleteObject: %v", err)
+	}
+	left := listJournal(t, s, owner, g.ID, JournalQuery{})
+	if len(left) != 1 || left[0].Body != "Garden-level note" {
+		t.Errorf("after deleting the bed the journal is %+v, want just the garden note", left)
+	}
+}
+
+// TestBackdatedEntriesOrderByObservationNotWriting — you write up Saturday's
+// observations on Sunday, and Saturday is the date that matters.
+func TestBackdatedEntriesOrderByObservationNotWriting(t *testing.T) {
+	s := newTestService(t, openConfig())
+	owner := seedUser(t, s, "[email protected]")
+	g := seedGarden(t, s, owner)
+
+	// Written second, observed first.
+	writeEntry(t, s, owner, g.ID, JournalInput{Body: "Sunday", ObservedAt: strPtr("2026-06-14")})
+	writeEntry(t, s, owner, g.ID, JournalInput{Body: "Saturday", ObservedAt: strPtr("2026-06-13")})
+	writeEntry(t, s, owner, g.ID, JournalInput{Body: "Monday", ObservedAt: strPtr("2026-06-15")})
+
+	got := listJournal(t, s, owner, g.ID, JournalQuery{})
+	want := []string{"Monday", "Sunday", "Saturday"}
+	for i, w := range want {
+		if got[i].Body != w {
+			t.Errorf("position %d = %q, want %q (ordered by observation, newest first)", i, got[i].Body, w)
+		}
+	}
+
+	// A date range filters on observation too.
+	from, to := "2026-06-14", "2026-06-14"
+	only := listJournal(t, s, owner, g.ID, JournalQuery{From: &from, To: &to})
+	if len(only) != 1 || only[0].Body != "Sunday" {
+		t.Errorf("date range returned %+v, want just Sunday", only)
+	}
+}
+
+// TestObservedAtDefaultsToToday
+func TestObservedAtDefaultsToToday(t *testing.T) {
+	s := newTestService(t, openConfig())
+	owner := seedUser(t, s, "[email protected]")
+	g := seedGarden(t, s, owner)
+
+	e := writeEntry(t, s, owner, g.ID, JournalInput{Body: "No date given"})
+	if e.ObservedAt != s.now().UTC().Format(dateLayout) {
+		t.Errorf("observedAt = %q, want today", e.ObservedAt)
+	}
+	if _, err := s.CreateJournalEntry(context.Background(), owner, g.ID, JournalInput{
+		Body: "Bad date", ObservedAt: strPtr("14/06/2026"),
+	}); !errors.Is(err, domain.ErrInvalidInput) {
+		t.Errorf("malformed observedAt accepted: %v", err)
+	}
+	if _, err := s.CreateJournalEntry(context.Background(), owner, g.ID, JournalInput{Body: "   "}); !errors.Is(err, domain.ErrInvalidInput) {
+		t.Errorf("empty body accepted: %v", err)
+	}
+}
+
+// TestJournalPermissions — viewer reads and cannot write; stranger sees nothing;
+// an author owns their own text, and the garden owner can remove anything.
+func TestJournalPermissions(t *testing.T) {
+	s := newTestService(t, openConfig())
+	owner := seedUser(t, s, "[email protected]")
+	editor := seedUser(t, s, "[email protected]")
+	viewer := seedUser(t, s, "[email protected]")
+	stranger := seedUser(t, s, "[email protected]")
+	g := seedGarden(t, s, owner)
+	ctx := context.Background()
+
+	if _, err := s.AddShare(ctx, owner, g.ID, "[email protected]", domain.RoleEditor); err != nil {
+		t.Fatalf("AddShare editor: %v", err)
+	}
+	if _, err := s.AddShare(ctx, owner, g.ID, "[email protected]", domain.RoleViewer); err != nil {
+		t.Fatalf("AddShare viewer: %v", err)
+	}
+
+	byEditor := writeEntry(t, s, editor, g.ID, JournalInput{Body: "Editor's observation"})
+
+	// Viewer: reads, cannot write.
+	if entries := listJournal(t, s, viewer, g.ID, JournalQuery{}); len(entries) != 1 {
+		t.Errorf("viewer sees %d entries, want 1", len(entries))
+	}
+	if _, err := s.CreateJournalEntry(ctx, viewer, g.ID, JournalInput{Body: "nope"}); !errors.Is(err, domain.ErrForbidden) {
+		t.Errorf("viewer write err = %v, want ErrForbidden", err)
+	}
+
+	// Stranger: existence stays masked.
+	if _, _, err := s.ListJournal(ctx, stranger, g.ID, JournalQuery{}); !errors.Is(err, domain.ErrNotFound) {
+		t.Errorf("stranger read err = %v, want ErrNotFound", err)
+	}
+	if err := s.DeleteJournalEntry(ctx, stranger, byEditor.ID); !errors.Is(err, domain.ErrNotFound) {
+		t.Errorf("stranger delete err = %v, want ErrNotFound", err)
+	}
+
+	// The author edits their own.
+	updated, err := s.UpdateJournalEntry(ctx, editor, byEditor.ID, JournalPatch{Body: strPtr("Revised")}, byEditor.Version)
+	if err != nil {
+		t.Fatalf("author edit: %v", err)
+	}
+	if updated.Body != "Revised" {
+		t.Errorf("body = %q", updated.Body)
+	}
+
+	// The garden OWNER may not rewrite somebody else's observation under their
+	// name — that's a different act from removing it.
+	if _, err := s.UpdateJournalEntry(ctx, owner, byEditor.ID, JournalPatch{Body: strPtr("Owner rewrote this")}, updated.Version); !errors.Is(err, domain.ErrForbidden) {
+		t.Errorf("owner edit of another's entry err = %v, want ErrForbidden", err)
+	}
+	// But may delete it: the owner is the backstop for content in their garden.
+	if err := s.DeleteJournalEntry(ctx, owner, byEditor.ID); err != nil {
+		t.Errorf("owner delete of another's entry: %v", err)
+	}
+}
+
+// TestEntryTargetMustBelongToTheGarden — the garden anchors permission, so an
+// object id from somebody else's garden must not be storable against this one.
+func TestEntryTargetMustBelongToTheGarden(t *testing.T) {
+	s := newTestService(t, openConfig())
+	owner := seedUser(t, s, "[email protected]")
+	other := seedUser(t, s, "[email protected]")
+	mine := seedGarden(t, s, owner)
+	theirs := seedGarden(t, s, other)
+	theirBed := seedBed(t, s, other, theirs.ID)
+	myBed := seedBed(t, s, owner, mine.ID)
+	ctx := context.Background()
+
+	if _, err := s.CreateJournalEntry(ctx, owner, mine.ID, JournalInput{
+		ObjectID: &theirBed.ID, Body: "about someone else's bed",
+	}); !errors.Is(err, domain.ErrInvalidInput) {
+		t.Errorf("foreign object accepted: %v", err)
+	}
+
+	// A plop-level entry naming the wrong object is refused too, or the object
+	// and planting filters would disagree about what an entry is about.
+	plant := seedOwnPlant(t, s, owner, 15)
+	otherBed, err := s.CreateObject(ctx, owner, mine.ID, ObjectInput{
+		Kind: domain.KindBed, Name: "Other", XCM: 200, YCM: 200, WidthCM: 100, HeightCM: 100,
+	})
+	if err != nil {
+		t.Fatalf("CreateObject: %v", err)
+	}
+	plop, err := s.CreatePlanting(ctx, owner, myBed.ID, PlantingInput{
+		PlantID: plant.ID, XCM: 0, YCM: 0, RadiusCM: 20,
+	})
+	if err != nil {
+		t.Fatalf("CreatePlanting: %v", err)
+	}
+	if _, err := s.CreateJournalEntry(ctx, owner, mine.ID, JournalInput{
+		ObjectID: &otherBed.ID, PlantingID: &plop.ID, Body: "mismatched",
+	}); !errors.Is(err, domain.ErrInvalidInput) {
+		t.Errorf("mismatched object/planting pair accepted: %v", err)
+	}
+}
+
+// TestJournalVersionGuardAndPaging
+func TestJournalVersionGuardAndPaging(t *testing.T) {
+	s := newTestService(t, openConfig())
+	owner := seedUser(t, s, "[email protected]")
+	g := seedGarden(t, s, owner)
+	ctx := context.Background()
+
+	e := writeEntry(t, s, owner, g.ID, JournalInput{Body: "One"})
+	if _, err := s.UpdateJournalEntry(ctx, owner, e.ID, JournalPatch{Body: strPtr("Two")}, e.Version); err != nil {
+		t.Fatalf("first update: %v", err)
+	}
+	current, err := s.UpdateJournalEntry(ctx, owner, e.ID, JournalPatch{Body: strPtr("Three")}, e.Version)
+	if !errors.Is(err, domain.ErrVersionConflict) {
+		t.Fatalf("stale update err = %v, want ErrVersionConflict", err)
+	}
+	if current == nil || current.Body != "Two" {
+		t.Errorf("conflict should carry the current row, got %+v", current)
+	}
+
+	for i := 0; i < 5; i++ {
+		writeEntry(t, s, owner, g.ID, JournalInput{Body: "filler"})
+	}
+	page, hasMore, err := s.ListJournal(ctx, owner, g.ID, JournalQuery{Limit: 2})
+	if err != nil {
+		t.Fatalf("ListJournal: %v", err)
+	}
+	if len(page) != 2 || !hasMore {
+		t.Errorf("page = %d entries, hasMore = %v; want 2 and true", len(page), hasMore)
+	}
+	last, hasMore, err := s.ListJournal(ctx, owner, g.ID, JournalQuery{Limit: 50, Offset: 0})
+	if err != nil {
+		t.Fatalf("ListJournal: %v", err)
+	}
+	if len(last) != 6 || hasMore {
+		t.Errorf("full page = %d entries, hasMore = %v; want 6 and false", len(last), hasMore)
+	}
+}
+
+// TestJournalStaysOutOfRevisionHistory — decided deliberately (#52): entries are
+// append-shaped and individually versioned, and undoing a note is deleting it.
+func TestJournalStaysOutOfRevisionHistory(t *testing.T) {
+	s := newTestService(t, openConfig())
+	owner := seedUser(t, s, "[email protected]")
+	g := seedGarden(t, s, owner)
+
+	before := len(history(t, s, owner, g.ID))
+	e := writeEntry(t, s, owner, g.ID, JournalInput{Body: "An observation"})
+	if _, err := s.UpdateJournalEntry(context.Background(), owner, e.ID, JournalPatch{Body: strPtr("Revised")}, e.Version); err != nil {
+		t.Fatalf("update: %v", err)
+	}
+	if got := len(history(t, s, owner, g.ID)); got != before {
+		t.Errorf("journal writes produced %d change sets; they should produce none", got-before)
+	}
+}
+
+// TestPlopEntryIsVisibleUnderItsBed — an entry about a plant IN a bed is an entry
+// about that bed. Without deriving the parent object, "notes about this bed"
+// would silently exclude every note written about something growing in it.
+func TestPlopEntryIsVisibleUnderItsBed(t *testing.T) {
+	s := newTestService(t, openConfig())
+	owner := seedUser(t, s, "[email protected]")
+	g := seedGarden(t, s, owner)
+	bed := seedBed(t, s, owner, g.ID)
+	plant := seedOwnPlant(t, s, owner, 15)
+	ctx := context.Background()
+
+	plop, err := s.CreatePlanting(ctx, owner, bed.ID, PlantingInput{
+		PlantID: plant.ID, XCM: 0, YCM: 0, RadiusCM: 20,
+	})
+	if err != nil {
+		t.Fatalf("CreatePlanting: %v", err)
+	}
+
+	// Only the plop is named — no objectId.
+	e := writeEntry(t, s, owner, g.ID, JournalInput{PlantingID: &plop.ID, Body: "Scapes forming"})
+	if e.ObjectID == nil || *e.ObjectID != bed.ID {
+		t.Fatalf("objectId = %v, want the plop's parent bed %d", e.ObjectID, bed.ID)
+	}
+	if byBed := listJournal(t, s, owner, g.ID, JournalQuery{ObjectID: &bed.ID}); len(byBed) != 1 {
+		t.Errorf("the bed filter found %d entries, want the plop's", len(byBed))
+	}
+	if byPlop := listJournal(t, s, owner, g.ID, JournalQuery{PlantingID: &plop.ID}); len(byPlop) != 1 {
+		t.Errorf("the plop filter found %d entries, want 1", len(byPlop))
+	}
+}

internal/store/journal.go

@@ -0,0 +1,168 @@
+package store
+
+import (
+	"context"
+	"database/sql"
+	"errors"
+	"fmt"
+
+	"gitea.stevedudenhoeffer.com/steve/pansy/internal/domain"
+)
+
+// journalColumns lists journal_entries columns in the order scanJournalEntry
+// expects. Used unqualified for direct selects; the list read qualifies with j.
+const journalColumns = `id, garden_id, object_id, planting_id, author_id, body,
+	observed_at, version, created_at, updated_at`
+
+// journalScanTargets returns the scan destinations for journalColumns, in order.
+// The list read appends one more for the joined author name, so the two readers
+// share a single definition of the column order rather than each repeating it.
+func journalScanTargets(e *domain.JournalEntry) []any {
+	return []any{
+		&e.ID, &e.GardenID, &e.ObjectID, &e.PlantingID, &e.AuthorID, &e.Body,
+		&e.ObservedAt, &e.Version, &e.CreatedAt, &e.UpdatedAt,
+	}
+}
+
+func scanJournalEntry(s scanner) (*domain.JournalEntry, error) {
+	var e domain.JournalEntry
+	if err := s.Scan(journalScanTargets(&e)...); err != nil {
+		return nil, err
+	}
+	return &e, nil
+}
+
+// JournalFilter narrows a garden's journal. A nil field means "don't filter on
+// this". ObjectID/PlantingID select entries about one bed or one plop; the date
+// range is inclusive and matches observed_at, not created_at.
+type JournalFilter struct {
+	ObjectID   *int64
+	PlantingID *int64
+	From       *string
+	To         *string
+	Limit      int
+	Offset     int
+}
+
+// CreateJournalEntry inserts an entry (fields already validated by the service).
+func (d *DB) CreateJournalEntry(ctx context.Context, e *domain.JournalEntry) (*domain.JournalEntry, error) {
+	created, err := scanJournalEntry(d.sql.QueryRowContext(ctx,
+		`INSERT INTO journal_entries (garden_id, object_id, planting_id, author_id, body, observed_at)
+		 VALUES (?, ?, ?, ?, ?, ?)
+		 RETURNING `+journalColumns,
+		e.GardenID, e.ObjectID, e.PlantingID, e.AuthorID, e.Body, e.ObservedAt,
+	))
+	if err != nil {
+		return nil, fmt.Errorf("store: insert journal entry: %w", err)
+	}
+	return created, nil
+}
+
+// GetJournalEntry returns an entry by id, or domain.ErrNotFound. Permission is
+// the service's business, via the entry's garden.
+func (d *DB) GetJournalEntry(ctx context.Context, id int64) (*domain.JournalEntry, error) {
+	e, err := scanJournalEntry(d.sql.QueryRowContext(ctx,
+		`SELECT `+journalColumns+` FROM journal_entries WHERE id = ?`, id))
+	if errors.Is(err, sql.ErrNoRows) {
+		return nil, domain.ErrNotFound
+	}
+	if err != nil {
+		return nil, fmt.Errorf("store: get journal entry: %w", err)
+	}
+	return e, nil
+}
+
+// ListJournalEntries returns a garden's entries, most recently OBSERVED first,
+// narrowed by the filter. Each carries its author's display name, so the list
+// renders without a lookup per row. Always a non-nil slice.
+func (d *DB) ListJournalEntries(ctx context.Context, gardenID int64, f JournalFilter) ([]domain.JournalEntry, error) {
+	query := `SELECT ` + qualifyColumns("j", journalColumns) + `, u.display_name
+		   FROM journal_entries j
+		   JOIN users u ON u.id = j.author_id
+		  WHERE j.garden_id = ?`
+	args := []any{gardenID}
+
+	if f.ObjectID != nil {
+		query += ` AND j.object_id = ?`
+		args = append(args, *f.ObjectID)
+	}
+	if f.PlantingID != nil {
+		query += ` AND j.planting_id = ?`
+		args = append(args, *f.PlantingID)
+	}
+	if f.From != nil {
+		query += ` AND j.observed_at >= ?`
+		args = append(args, *f.From)
+	}
+	if f.To != nil {
+		query += ` AND j.observed_at <= ?`
+		args = append(args, *f.To)
+	}
+	// id DESC breaks ties within a day, so several entries observed on the same
+	// date still read newest-first rather than in arbitrary order.
+	query += ` ORDER BY j.observed_at DESC, j.id DESC LIMIT ? OFFSET ?`
+	args = append(args, f.Limit, f.Offset)
+
+	rows, err := d.sql.QueryContext(ctx, query, args...)
+	if err != nil {
+		return nil, fmt.Errorf("store: list journal entries: %w", err)
+	}
+	defer rows.Close()
+
+	entries := []domain.JournalEntry{}
+	for rows.Next() {
+		var e domain.JournalEntry
+		if err := rows.Scan(append(journalScanTargets(&e), &e.AuthorName)...); err != nil {
+			return nil, fmt.Errorf("store: scan journal entry: %w", err)
+		}
+		entries = append(entries, e)
+	}
+	if err := rows.Err(); err != nil {
+		return nil, fmt.Errorf("store: iterate journal entries: %w", err)
+	}
+	return entries, nil
+}
+
+// UpdateJournalEntry applies a version-guarded update of the mutable columns.
+// Same contract as every other mutable resource. The target (garden/object/
+// planting) and the author are immutable: an entry is a record of an observation,
+// so re-pointing it at a different bed would be rewriting the observation rather
+// than correcting the text.
+func (d *DB) UpdateJournalEntry(ctx context.Context, e *domain.JournalEntry) (*domain.JournalEntry, error) {
+	updated, err := scanJournalEntry(d.sql.QueryRowContext(ctx,
+		`UPDATE journal_entries
+		    SET body = ?, observed_at = ?,
+		        version = version + 1,
+		        updated_at = strftime('%Y-%m-%dT%H:%M:%SZ', 'now')
+		  WHERE id = ? AND version = ?
+		  RETURNING `+journalColumns,
+		e.Body, e.ObservedAt, e.ID, e.Version,
+	))
+	if errors.Is(err, sql.ErrNoRows) {
+		current, gerr := d.GetJournalEntry(ctx, e.ID)
+		if gerr != nil {
+			return nil, gerr
+		}
+		return current, domain.ErrVersionConflict
+	}
+	if err != nil {
+		return nil, fmt.Errorf("store: update journal entry: %w", err)
+	}
+	return updated, nil
+}
+
+// DeleteJournalEntry removes an entry. Returns domain.ErrNotFound if none was.
+func (d *DB) DeleteJournalEntry(ctx context.Context, id int64) error {
+	res, err := d.sql.ExecContext(ctx, `DELETE FROM journal_entries WHERE id = ?`, id)
+	if err != nil {
+		return fmt.Errorf("store: delete journal entry: %w", err)
+	}
+	n, err := res.RowsAffected()
+	if err != nil {
+		return fmt.Errorf("store: journal delete rows: %w", err)
+	}
+	if n == 0 {
+		return domain.ErrNotFound
+	}
+	return nil
+}

internal/store/migrations/0008_journal.sql

@@ -0,0 +1,33 @@
+-- Grow journal (#52): time-stamped notes on gardens, beds and plantings.
+--
+-- There is already free-text `notes` on gardens, objects and plants, but it is a
+-- single mutable field: writing "powdery mildew on the west bed" overwrites what
+-- you wrote in June. The distinction worth keeping is that `notes` is WHAT THIS
+-- THING IS, while a journal entry is WHAT HAPPENED, AND WHEN. Both stay.
+--
+-- garden_id is NOT NULL even when the entry is about a bed or a single plop, and
+-- that is the whole trick: permission checks reuse requireGardenRole unchanged
+-- and no new ACL path is invented. object_id/planting_id narrow the target; the
+-- garden always anchors it.
+--
+-- observed_at is deliberately distinct from created_at — you write up Saturday's
+-- observations on Sunday, and the date that matters is Saturday's.
+CREATE TABLE journal_entries (
+    id          INTEGER PRIMARY KEY,
+    garden_id   INTEGER NOT NULL REFERENCES gardens (id)        ON DELETE CASCADE,
+    object_id   INTEGER          REFERENCES garden_objects (id) ON DELETE CASCADE,
+    planting_id INTEGER          REFERENCES plantings (id)      ON DELETE CASCADE,
+    author_id   INTEGER NOT NULL REFERENCES users (id)          ON DELETE CASCADE,
+    body        TEXT    NOT NULL,
+    observed_at TEXT    NOT NULL,                               -- 'YYYY-MM-DD'
+    version     INTEGER NOT NULL DEFAULT 1,
+    created_at  TEXT    NOT NULL DEFAULT (strftime('%Y-%m-%dT%H:%M:%SZ', 'now')),
+    updated_at  TEXT    NOT NULL DEFAULT (strftime('%Y-%m-%dT%H:%M:%SZ', 'now'))
+);
+
+-- The journal's only list query: one garden, most recently observed first.
+CREATE INDEX idx_journal_garden ON journal_entries (garden_id, observed_at DESC);
+
+-- Narrowing to one bed or one plop.
+CREATE INDEX idx_journal_object ON journal_entries (object_id) WHERE object_id IS NOT NULL;
+CREATE INDEX idx_journal_planting ON journal_entries (planting_id) WHERE planting_id IS NOT NULL;