Seed provenance and inventory: source links and seed lots (#50)

"German Red Garlic" now links back to the Johnny's page it came from, and pansy
knows how much is left.

Two modelling calls, both of which look like omissions unless stated.

The plant catalog stays FLAT — no species/variety hierarchy. A row in your
catalog just is the thing you plant; the built-in "Garlic" is a generic starting
point you clone. A hierarchy buys taxonomy nobody asked for and complicates
every join.

Inventory belongs to a PURCHASE, not to a variety. You might buy the same garlic
from two vendors in two years at two prices and two germination rates; quantity
columns on plants would collapse all of that into one number and lose it. So
lots get their own table, and owner_id sits on the lot rather than being
inherited from the plant — you can buy generic built-in Garlic from Johnny's and
the record is still yours alone. Lots are never shared along with a garden.

`remaining` is derived, never stored: quantity minus the summed effective count
of the active plantings attributed to the lot. The alternative — decrementing a
column when you plant — drifts the moment anything edits or removes a planting
behind its back, and once it has drifted there's no way to tell what the true
number was. Removing a plop gives the seed back with nothing having to remember
to. The usage query returns raw radius/count/spacing rather than a SUM, because
the effective-count formula lives in the service and reproducing it in SQL would
guarantee the two drift apart.

source_url is validated as http(s) with a host, on both plants and lots. It
renders as a clickable link, so that check is load-bearing rather than tidiness:
without it a stored javascript: URL becomes script execution the moment someone
clicks it. Schemeless and relative URLs are refused too — they'd resolve against
pansy's own origin, which is never what a vendor link means.

A planting's lot must be the actor's AND a lot of the plant being planted.
Attributing a garlic planting to a tomato lot would silently corrupt every
remaining count downstream, so it's refused rather than stored, and re-checked
on update in case a plant swap invalidated a previously-valid attribution.

Deleting a lot leaves its plantings alone with a null link: the plants really
were in the ground, whatever happened to the record of the packet.

Closes #50

Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>
Claude-Session: https://claude.ai/code/session_01H3zbym8Doka2d7D48maSgZ

internal/service/plantings.go

@@ -50,6 +50,9 @@ type PlantingInput struct {
 	Count     *int
 	Label     *string
 	PlantedAt *string
+	// SeedLotID attributes this planting to a purchase, so the lot can report
+	// what's left. Optional.
+	SeedLotID *int64
 }
 
 // PlantingPatch is a partial update. The nullable fields (Count/Label/PlantedAt/
@@ -68,6 +71,8 @@ type PlantingPatch struct {
 	PlantedAt    *string
 	SetRemovedAt bool
 	RemovedAt    *string
+	SetSeedLotID bool
+	SeedLotID    *int64
 }
 
 // CreatePlanting places a plop in a plantable object the actor can edit.
@@ -93,6 +98,7 @@ func (s *Service) CreatePlanting(ctx context.Context, actorID, objectID int64, i
 		Count:     in.Count,
 		Label:     trimStringPtr(in.Label),
 		PlantedAt: in.PlantedAt,
+		SeedLotID: in.SeedLotID,
 	}
 	if p.PlantedAt == nil {
 		today := s.now().UTC().Format(dateLayout)
@@ -101,6 +107,9 @@ func (s *Service) CreatePlanting(ctx context.Context, actorID, objectID int64, i
 	if err := finalizePlanting(p, o, true); err != nil {
 		return nil, err
 	}
+	if err := s.seedLotForPlanting(ctx, actorID, p.SeedLotID, p.PlantID); err != nil {
+		return nil, err
+	}
 	created, err := s.store.CreatePlanting(ctx, p)
 	if err != nil {
 		return nil, err
@@ -148,6 +157,11 @@ func (s *Service) UpdatePlanting(ctx context.Context, actorID, plantingID int64,
 	if err := finalizePlanting(pl, o, checkBounds); err != nil {
 		return nil, err
 	}
+	// Re-checked on every update, not just when the lot changes: a plant swap can
+	// leave a previously-valid attribution pointing at a lot of the wrong variety.
+	if err := s.seedLotForPlanting(ctx, actorID, pl.SeedLotID, pl.PlantID); err != nil {
+		return nil, err
+	}
 	pl.Version = version
 
 	updated, err := s.store.UpdatePlanting(ctx, pl)
@@ -249,6 +263,9 @@ func applyPlantingPatch(pl *domain.Planting, p PlantingPatch) {
 	if p.SetRemovedAt {
 		pl.RemovedAt = p.RemovedAt
 	}
+	if p.SetSeedLotID {
+		pl.SeedLotID = p.SeedLotID
+	}
 }
 
 // finalizePlanting validates a built/merged plop against its parent object.

internal/service/plants.go

@@ -40,7 +40,11 @@ type PlantInput struct {
 	Color          string
 	Icon           string
 	DaysToMaturity *int
-	Notes          string
+	// Where this variety came from — the page you'd go back to to buy it again.
+	// What you actually bought, and how much is left, is a SeedLot instead.
+	SourceURL string
+	Vendor    string
+	Notes     string
 }
 
 // PlantPatch is a partial update: nil fields are left unchanged. DaysToMaturity
@@ -54,6 +58,8 @@ type PlantPatch struct {
 	Icon           *string
 	SetDays        bool
 	DaysToMaturity *int
+	SourceURL      *string
+	Vendor         *string
 	Notes          *string
 }
 
@@ -73,6 +79,8 @@ func (s *Service) CreatePlant(ctx context.Context, actorID int64, in PlantInput)
 		Color:          in.Color,
 		Icon:           strings.TrimSpace(in.Icon),
 		DaysToMaturity: in.DaysToMaturity,
+		SourceURL:      strings.TrimSpace(in.SourceURL),
+		Vendor:         strings.TrimSpace(in.Vendor),
 		Notes:          strings.TrimSpace(in.Notes),
 	}
 	if err := finalizePlant(p); err != nil {
@@ -155,6 +163,12 @@ func applyPlantPatch(p *domain.Plant, patch PlantPatch) {
 	if patch.SetDays {
 		p.DaysToMaturity = patch.DaysToMaturity
 	}
+	if patch.SourceURL != nil {
+		p.SourceURL = strings.TrimSpace(*patch.SourceURL)
+	}
+	if patch.Vendor != nil {
+		p.Vendor = strings.TrimSpace(*patch.Vendor)
+	}
 	if patch.Notes != nil {
 		p.Notes = strings.TrimSpace(*patch.Notes)
 	}
@@ -184,5 +198,13 @@ func finalizePlant(p *domain.Plant) error {
 	if len(p.Notes) > maxPlantNotesLen {
 		return domain.ErrInvalidInput
 	}
+	if len(p.Vendor) > maxLotTextLen {
+		return domain.ErrInvalidInput
+	}
+	// Rendered as a clickable link, so the scheme check is load-bearing (see
+	// validSourceURL) rather than tidiness.
+	if !validSourceURL(p.SourceURL) {
+		return domain.ErrInvalidInput
+	}
 	return nil
 }

internal/service/plants_test.go

@@ -184,12 +184,12 @@ func TestCreatePlantValidation(t *testing.T) {
 	owner := seedUser(t, s, "[email protected]")
 
 	bad := []PlantInput{
-		{Name: "", Category: domain.CategoryHerb, SpacingCM: 10, Color: "#4a7c3f", Icon: "🌿"},         // empty name
-		{Name: "x", Category: "spaceship", SpacingCM: 10, Color: "#4a7c3f", Icon: "🌿"},                // bad category
-		{Name: "x", Category: domain.CategoryHerb, SpacingCM: 0, Color: "#4a7c3f", Icon: "🌿"},         // zero spacing
-		{Name: "x", Category: domain.CategoryHerb, SpacingCM: -5, Color: "#4a7c3f", Icon: "🌿"},        // negative spacing
-		{Name: "x", Category: domain.CategoryHerb, SpacingCM: 10, Color: "nope", Icon: "🌿"},           // bad color
-		{Name: "x", Category: domain.CategoryHerb, SpacingCM: 10, Color: "#4a7c3f", Icon: ""},          // empty icon
+		{Name: "", Category: domain.CategoryHerb, SpacingCM: 10, Color: "#4a7c3f", Icon: "🌿"},                                     // empty name
+		{Name: "x", Category: "spaceship", SpacingCM: 10, Color: "#4a7c3f", Icon: "🌿"},                                            // bad category
+		{Name: "x", Category: domain.CategoryHerb, SpacingCM: 0, Color: "#4a7c3f", Icon: "🌿"},                                     // zero spacing
+		{Name: "x", Category: domain.CategoryHerb, SpacingCM: -5, Color: "#4a7c3f", Icon: "🌿"},                                    // negative spacing
+		{Name: "x", Category: domain.CategoryHerb, SpacingCM: 10, Color: "nope", Icon: "🌿"},                                       // bad color
+		{Name: "x", Category: domain.CategoryHerb, SpacingCM: 10, Color: "#4a7c3f", Icon: ""},                                     // empty icon
 		{Name: strings.Repeat("x", maxPlantNameLen+1), Category: domain.CategoryHerb, SpacingCM: 10, Color: "#4a7c3f", Icon: "🌿"}, // name too long
 		{Name: "x", Category: domain.CategoryHerb, SpacingCM: 10, Color: "#4a7c3f", Icon: "🌿", DaysToMaturity: ptrInt(0)},         // days must be >= 1
 	}

internal/service/seed_lots.go

@@ -0,0 +1,314 @@
+package service
+
+import (
+	"context"
+	"net/url"
+	"strings"
+
+	"gitea.stevedudenhoeffer.com/steve/pansy/internal/domain"
+)
+
+// Seed provenance and inventory (#50). A lot is one purchase — a specific packet
+// of a specific variety, from a specific vendor, in a specific year — and it is
+// owned by the buyer even when it points at a built-in plant. Lots are private:
+// they are never shared along with a garden, because what you paid for seed is
+// not part of a garden plan.
+
+const (
+	maxLotTextLen   = 200
+	maxLotNotesLen  = 10_000
+	maxSourceURLLen = 2000
+	maxLotQuantity  = 1_000_000
+	minPackedYear   = 1900
+	maxPackedYear   = 2200
+)
+
+// lotUnits is the set of valid quantity units (mirrors the schema CHECK).
+var lotUnits = map[string]struct{}{
+	domain.UnitSeeds:   {},
+	domain.UnitGrams:   {},
+	domain.UnitOunces:  {},
+	domain.UnitPackets: {},
+	domain.UnitBulbs:   {},
+	domain.UnitPlants:  {},
+}
+
+// SeedLotInput is the payload for recording a purchase.
+type SeedLotInput struct {
+	PlantID        int64
+	Vendor         string
+	SourceURL      string
+	SKU            string
+	LotCode        string
+	PurchasedAt    *string
+	PackedForYear  *int
+	Quantity       float64
+	Unit           string
+	CostCents      *int
+	GerminationPct *float64
+	Notes          string
+}
+
+// SeedLotPatch is a partial update; nil fields are left unchanged. The nullable
+// columns use a Set* flag to tell "clear to NULL" from "leave alone". PlantID is
+// absent deliberately: re-pointing a purchase at a different variety would
+// rewrite history rather than correct it.
+type SeedLotPatch struct {
+	Vendor            *string
+	SourceURL         *string
+	SKU               *string
+	LotCode           *string
+	SetPurchasedAt    bool
+	PurchasedAt       *string
+	SetPackedForYear  bool
+	PackedForYear     *int
+	Quantity          *float64
+	Unit              *string
+	SetCostCents      bool
+	CostCents         *int
+	SetGerminationPct bool
+	GerminationPct    *float64
+	Notes             *string
+}
+
+// ListSeedLots returns the actor's own lots, each with Used/Remaining filled in.
+// Optionally narrowed to one plant.
+func (s *Service) ListSeedLots(ctx context.Context, actorID int64, plantID *int64) ([]domain.SeedLot, error) {
+	lots, err := s.store.ListSeedLotsForOwner(ctx, actorID, plantID)
+	if err != nil {
+		return nil, err
+	}
+	if err := s.fillRemaining(ctx, actorID, lots); err != nil {
+		return nil, err
+	}
+	return lots, nil
+}
+
+// fillRemaining computes Used and Remaining for a slice of the actor's lots.
+//
+// Deliberately derived, never stored. The alternative — decrementing a column
+// when you plant — drifts the moment anything edits or removes a planting behind
+// its back, and once it has drifted there is no way to tell what the true number
+// was. Attribution plus arithmetic can always be recomputed and audited.
+func (s *Service) fillRemaining(ctx context.Context, actorID int64, lots []domain.SeedLot) error {
+	if len(lots) == 0 {
+		return nil
+	}
+	uses, err := s.store.SeedLotUsage(ctx, actorID)
+	if err != nil {
+		return err
+	}
+	used := make(map[int64]float64, len(lots))
+	for _, u := range uses {
+		n := derivedCount(u.RadiusCM, u.SpacingCM)
+		if u.Count != nil {
+			n = *u.Count
+		}
+		used[u.LotID] += float64(n)
+	}
+	for i := range lots {
+		lots[i].Used = used[lots[i].ID]
+		lots[i].Remaining = lots[i].Quantity - lots[i].Used
+	}
+	return nil
+}
+
+// ownSeedLot loads a lot and enforces that the actor owns it. Someone else's lot
+// is ErrNotFound, not ErrForbidden — existence stays masked, same as gardens and
+// other users' plants.
+func (s *Service) ownSeedLot(ctx context.Context, actorID, lotID int64) (*domain.SeedLot, error) {
+	l, err := s.store.GetSeedLot(ctx, lotID)
+	if err != nil {
+		return nil, err // ErrNotFound
+	}
+	if l.OwnerID != actorID {
+		return nil, domain.ErrNotFound
+	}
+	return l, nil
+}
+
+// GetSeedLot returns one of the actor's own lots, with Used/Remaining filled in.
+func (s *Service) GetSeedLot(ctx context.Context, actorID, lotID int64) (*domain.SeedLot, error) {
+	l, err := s.ownSeedLot(ctx, actorID, lotID)
+	if err != nil {
+		return nil, err
+	}
+	one := []domain.SeedLot{*l}
+	if err := s.fillRemaining(ctx, actorID, one); err != nil {
+		return nil, err
+	}
+	return &one[0], nil
+}
+
+// CreateSeedLot records a purchase owned by the actor. The plant must be one the
+// actor can see — a built-in or their own — since you can perfectly well buy
+// generic Garlic from a vendor.
+func (s *Service) CreateSeedLot(ctx context.Context, actorID int64, in SeedLotInput) (*domain.SeedLot, error) {
+	if _, err := s.visiblePlant(ctx, actorID, in.PlantID); err != nil {
+		return nil, err // ErrInvalidInput for an unknown or someone else's plant
+	}
+	l := &domain.SeedLot{
+		OwnerID:        actorID,
+		PlantID:        in.PlantID,
+		Vendor:         strings.TrimSpace(in.Vendor),
+		SourceURL:      strings.TrimSpace(in.SourceURL),
+		SKU:            strings.TrimSpace(in.SKU),
+		LotCode:        strings.TrimSpace(in.LotCode),
+		PurchasedAt:    in.PurchasedAt,
+		PackedForYear:  in.PackedForYear,
+		Quantity:       in.Quantity,
+		Unit:           in.Unit,
+		CostCents:      in.CostCents,
+		GerminationPct: in.GerminationPct,
+		Notes:          strings.TrimSpace(in.Notes),
+	}
+	if err := finalizeSeedLot(l); err != nil {
+		return nil, err
+	}
+	return s.store.CreateSeedLot(ctx, l)
+}
+
+// UpdateSeedLot applies a partial, version-guarded patch to the actor's own lot.
+func (s *Service) UpdateSeedLot(ctx context.Context, actorID, lotID int64, patch SeedLotPatch, version int64) (*domain.SeedLot, error) {
+	l, err := s.ownSeedLot(ctx, actorID, lotID)
+	if err != nil {
+		return nil, err
+	}
+	applySeedLotPatch(l, patch)
+	if err := finalizeSeedLot(l); err != nil {
+		return nil, err
+	}
+	l.Version = version
+	updated, err := s.store.UpdateSeedLot(ctx, l)
+	if err != nil {
+		return updated, err
+	}
+	one := []domain.SeedLot{*updated}
+	if ferr := s.fillRemaining(ctx, actorID, one); ferr != nil {
+		return nil, ferr
+	}
+	return &one[0], nil
+}
+
+// DeleteSeedLot removes the actor's own lot. Plantings attributed to it survive
+// with a null link (ON DELETE SET NULL) — the plants really were in the ground,
+// whatever happened to the record of the packet.
+func (s *Service) DeleteSeedLot(ctx context.Context, actorID, lotID int64) error {
+	if _, err := s.ownSeedLot(ctx, actorID, lotID); err != nil {
+		return err
+	}
+	return s.store.DeleteSeedLot(ctx, lotID)
+}
+
+// seedLotForPlanting validates a planting's lot attribution: the lot must be the
+// actor's, and must be a lot OF the plant being planted. Attributing a garlic
+// planting to a tomato lot is a data error that would silently corrupt every
+// remaining count downstream, so it's refused rather than stored.
+func (s *Service) seedLotForPlanting(ctx context.Context, actorID int64, lotID *int64, plantID int64) error {
+	if lotID == nil {
+		return nil
+	}
+	l, err := s.ownSeedLot(ctx, actorID, *lotID)
+	if err != nil {
+		return domain.ErrInvalidInput // unknown or not yours: an invalid reference
+	}
+	if l.PlantID != plantID {
+		return domain.ErrInvalidInput
+	}
+	return nil
+}
+
+func applySeedLotPatch(l *domain.SeedLot, p SeedLotPatch) {
+	if p.Vendor != nil {
+		l.Vendor = strings.TrimSpace(*p.Vendor)
+	}
+	if p.SourceURL != nil {
+		l.SourceURL = strings.TrimSpace(*p.SourceURL)
+	}
+	if p.SKU != nil {
+		l.SKU = strings.TrimSpace(*p.SKU)
+	}
+	if p.LotCode != nil {
+		l.LotCode = strings.TrimSpace(*p.LotCode)
+	}
+	if p.SetPurchasedAt {
+		l.PurchasedAt = p.PurchasedAt
+	}
+	if p.SetPackedForYear {
+		l.PackedForYear = p.PackedForYear
+	}
+	if p.Quantity != nil {
+		l.Quantity = *p.Quantity
+	}
+	if p.Unit != nil {
+		l.Unit = *p.Unit
+	}
+	if p.SetCostCents {
+		l.CostCents = p.CostCents
+	}
+	if p.SetGerminationPct {
+		l.GerminationPct = p.GerminationPct
+	}
+	if p.Notes != nil {
+		l.Notes = strings.TrimSpace(*p.Notes)
+	}
+}
+
+// finalizeSeedLot validates a built/merged lot. Shared by create and update.
+func finalizeSeedLot(l *domain.SeedLot) error {
+	if _, ok := lotUnits[l.Unit]; !ok {
+		return domain.ErrInvalidInput
+	}
+	if !isFinite(l.Quantity) || l.Quantity < 0 || l.Quantity > maxLotQuantity {
+		return domain.ErrInvalidInput
+	}
+	if len(l.Vendor) > maxLotTextLen || len(l.SKU) > maxLotTextLen || len(l.LotCode) > maxLotTextLen {
+		return domain.ErrInvalidInput
+	}
+	if len(l.Notes) > maxLotNotesLen {
+		return domain.ErrInvalidInput
+	}
+	if !validSourceURL(l.SourceURL) {
+		return domain.ErrInvalidInput
+	}
+	if !validDatePtr(l.PurchasedAt) {
+		return domain.ErrInvalidInput
+	}
+	if l.PackedForYear != nil && (*l.PackedForYear < minPackedYear || *l.PackedForYear > maxPackedYear) {
+		return domain.ErrInvalidInput
+	}
+	if l.CostCents != nil && *l.CostCents < 0 {
+		return domain.ErrInvalidInput
+	}
+	if l.GerminationPct != nil {
+		g := *l.GerminationPct
+		if !isFinite(g) || g < 0 || g > 100 {
+			return domain.ErrInvalidInput
+		}
+	}
+	return nil
+}
+
+// validSourceURL accepts an empty string or an absolute http(s) URL.
+//
+// This renders as a clickable link, so it is untrusted input in the way that
+// matters: without the scheme check a "javascript:" URL stored here becomes
+// script execution the moment someone clicks it. Only http and https, and only
+// with a host — a relative or schemeless URL would resolve against pansy's own
+// origin, which is never what a vendor link means.
+func validSourceURL(raw string) bool {
+	if raw == "" {
+		return true
+	}
+	if len(raw) > maxSourceURLLen {
+		return false
+	}
+	u, err := url.Parse(raw)
+	if err != nil {
+		return false
+	}
+	if u.Scheme != "http" && u.Scheme != "https" {
+		return false
+	}
+	return u.Host != ""
+}

internal/service/seed_lots_test.go

@@ -0,0 +1,345 @@
+package service
+
+import (
+	"context"
+	"errors"
+	"testing"
+
+	"gitea.stevedudenhoeffer.com/steve/pansy/internal/domain"
+)
+
+// seedLot records a purchase of plantID with the given quantity in seeds.
+func seedLot(t *testing.T, s *Service, owner, plantID int64, qty float64, over func(*SeedLotInput)) *domain.SeedLot {
+	t.Helper()
+	in := SeedLotInput{PlantID: plantID, Quantity: qty, Unit: domain.UnitSeeds}
+	if over != nil {
+		over(&in)
+	}
+	l, err := s.CreateSeedLot(context.Background(), owner, in)
+	if err != nil {
+		t.Fatalf("CreateSeedLot: %v", err)
+	}
+	return l
+}
+
+// builtinPlantID returns a seeded built-in's id — the case that proves a lot can
+// reference a plant it doesn't own.
+func builtinPlantID(t *testing.T, s *Service, actor int64) int64 {
+	t.Helper()
+	plants, err := s.ListPlants(context.Background(), actor)
+	if err != nil {
+		t.Fatalf("ListPlants: %v", err)
+	}
+	for _, p := range plants {
+		if p.OwnerID == nil {
+			return p.ID
+		}
+	}
+	t.Fatal("no built-in plants seeded")
+	return 0
+}
+
+// TestTwoLotsOfOnePlantTrackIndependently — the reason inventory belongs to a
+// purchase and not to a variety: the same garlic from two vendors in two years
+// is two different things.
+func TestTwoLotsOfOnePlantTrackIndependently(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()
+
+	johnnys := seedLot(t, s, owner, plant.ID, 100, func(in *SeedLotInput) {
+		in.Vendor = "Johnny's"
+		in.SourceURL = "https://www.johnnyseeds.com/vegetables/garlic/german-red-garlic"
+		in.PackedForYear = intPtr(2026)
+	})
+	fedco := seedLot(t, s, owner, plant.ID, 50, func(in *SeedLotInput) {
+		in.Vendor = "Fedco"
+		in.PackedForYear = intPtr(2025)
+	})
+
+	// Plant 12 out of the Johnny's lot only.
+	twelve := 12
+	if _, err := s.CreatePlanting(ctx, owner, bed.ID, PlantingInput{
+		PlantID: plant.ID, XCM: 0, YCM: 0, RadiusCM: 20, Count: &twelve, SeedLotID: &johnnys.ID,
+	}); err != nil {
+		t.Fatalf("CreatePlanting: %v", err)
+	}
+
+	lots, err := s.ListSeedLots(ctx, owner, nil)
+	if err != nil {
+		t.Fatalf("ListSeedLots: %v", err)
+	}
+	byID := map[int64]domain.SeedLot{}
+	for _, l := range lots {
+		byID[l.ID] = l
+	}
+	if got := byID[johnnys.ID]; got.Used != 12 || got.Remaining != 88 {
+		t.Errorf("Johnny's lot: used=%v remaining=%v, want 12/88", got.Used, got.Remaining)
+	}
+	if got := byID[fedco.ID]; got.Used != 0 || got.Remaining != 50 {
+		t.Errorf("Fedco lot: used=%v remaining=%v, want 0/50", got.Used, got.Remaining)
+	}
+	if byID[johnnys.ID].Vendor != "Johnny's" || byID[johnnys.ID].SourceURL == "" {
+		t.Errorf("provenance lost: %+v", byID[johnnys.ID])
+	}
+}
+
+// TestRemainingReturnsWhenAPlantingIsRemoved — the acceptance criterion, and the
+// reason `remaining` is derived rather than decremented on planting: removing a
+// plop has to give the seed back, without anything having to remember to.
+func TestRemainingReturnsWhenAPlantingIsRemoved(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)
+	lot := seedLot(t, s, owner, plant.ID, 100, nil)
+	ctx := context.Background()
+
+	ten := 10
+	pl, err := s.CreatePlanting(ctx, owner, bed.ID, PlantingInput{
+		PlantID: plant.ID, XCM: 0, YCM: 0, RadiusCM: 20, Count: &ten, SeedLotID: &lot.ID,
+	})
+	if err != nil {
+		t.Fatalf("CreatePlanting: %v", err)
+	}
+	if got, _ := s.GetSeedLot(ctx, owner, lot.ID); got.Remaining != 90 {
+		t.Fatalf("remaining after planting = %v, want 90", got.Remaining)
+	}
+
+	// Soft-remove ("cleared the bed"): only ACTIVE plantings count against a lot.
+	today := "2026-08-01"
+	if _, err := s.UpdatePlanting(ctx, owner, pl.ID, PlantingPatch{
+		SetRemovedAt: true, RemovedAt: &today,
+	}, pl.Version); err != nil {
+		t.Fatalf("UpdatePlanting: %v", err)
+	}
+	if got, _ := s.GetSeedLot(ctx, owner, lot.ID); got.Remaining != 100 || got.Used != 0 {
+		t.Errorf("after removal: used=%v remaining=%v, want 0/100", got.Used, got.Remaining)
+	}
+}
+
+// TestLotOnBuiltinPlantIsPrivate — you can buy generic Garlic from Johnny's, so
+// a lot may point at a plant it doesn't own; the LOT is still yours alone.
+func TestLotOnBuiltinPlantIsPrivate(t *testing.T) {
+	s := newTestService(t, openConfig())
+	owner := seedUser(t, s, "[email protected]")
+	other := seedUser(t, s, "[email protected]")
+	ctx := context.Background()
+
+	builtin := builtinPlantID(t, s, owner)
+	lot := seedLot(t, s, owner, builtin, 25, func(in *SeedLotInput) { in.Vendor = "Johnny's" })
+
+	if _, err := s.GetSeedLot(ctx, owner, lot.ID); err != nil {
+		t.Fatalf("owner can't read their own lot: %v", err)
+	}
+	// Another user gets ErrNotFound, not Forbidden: existence stays masked.
+	if _, err := s.GetSeedLot(ctx, other, lot.ID); !errors.Is(err, domain.ErrNotFound) {
+		t.Errorf("other user read err = %v, want ErrNotFound", err)
+	}
+	if _, err := s.UpdateSeedLot(ctx, other, lot.ID, SeedLotPatch{Notes: strPtr("mine now")}, lot.Version); !errors.Is(err, domain.ErrNotFound) {
+		t.Errorf("other user update err = %v, want ErrNotFound", err)
+	}
+	if err := s.DeleteSeedLot(ctx, other, lot.ID); !errors.Is(err, domain.ErrNotFound) {
+		t.Errorf("other user delete err = %v, want ErrNotFound", err)
+	}
+	if lots, _ := s.ListSeedLots(ctx, other, nil); len(lots) != 0 {
+		t.Errorf("other user sees %d lots", len(lots))
+	}
+}
+
+// TestSourceURLValidation — the field renders as a clickable link, so the scheme
+// check is what stops a stored javascript: URL from becoming script execution.
+func TestSourceURLValidation(t *testing.T) {
+	s := newTestService(t, openConfig())
+	owner := seedUser(t, s, "[email protected]")
+	plant := seedOwnPlant(t, s, owner, 15)
+	ctx := context.Background()
+
+	ok := []string{
+		"",
+		"https://www.johnnyseeds.com/x",
+		"http://example.com/seeds?sku=123",
+	}
+	for _, u := range ok {
+		if _, err := s.CreateSeedLot(ctx, owner, SeedLotInput{
+			PlantID: plant.ID, Unit: domain.UnitSeeds, SourceURL: u,
+		}); err != nil {
+			t.Errorf("SourceURL %q rejected: %v", u, err)
+		}
+	}
+	bad := []string{
+		"javascript:alert(1)",
+		"JavaScript:alert(1)",
+		"data:text/html,<script>alert(1)</script>",
+		"//evil.example.com", // schemeless: would resolve against pansy's origin
+		"/seeds/garlic",      // relative, same reason
+		"file:///etc/passwd",
+		"https://", // no host
+	}
+	for _, u := range bad {
+		if _, err := s.CreateSeedLot(ctx, owner, SeedLotInput{
+			PlantID: plant.ID, Unit: domain.UnitSeeds, SourceURL: u,
+		}); !errors.Is(err, domain.ErrInvalidInput) {
+			t.Errorf("SourceURL %q accepted (err=%v)", u, err)
+		}
+	}
+	// The same rule applies to the plant's own source link.
+	if _, err := s.CreatePlant(ctx, owner, PlantInput{
+		Name: "X", Category: domain.CategoryHerb, SpacingCM: 10, Color: "#4a7c3f", Icon: "🌿",
+		SourceURL: "javascript:alert(1)",
+	}); !errors.Is(err, domain.ErrInvalidInput) {
+		t.Errorf("plant SourceURL accepted a javascript: URL (err=%v)", err)
+	}
+}
+
+// TestPlantCarriesProvenance — the headline: "German Red Garlic" links back to
+// the page it came from, and the built-ins keep working untouched.
+func TestPlantCarriesProvenance(t *testing.T) {
+	s := newTestService(t, openConfig())
+	owner := seedUser(t, s, "[email protected]")
+	ctx := context.Background()
+
+	p, err := s.CreatePlant(ctx, owner, PlantInput{
+		Name: "German Red Garlic", Category: domain.CategoryVegetable, SpacingCM: 15,
+		Color: "#8a5a8a", Icon: "🧄",
+		SourceURL: "https://www.johnnyseeds.com/vegetables/garlic/german-red-garlic",
+		Vendor:    "Johnny's Selected Seeds",
+	})
+	if err != nil {
+		t.Fatalf("CreatePlant: %v", err)
+	}
+	if p.Vendor != "Johnny's Selected Seeds" || p.SourceURL == "" {
+		t.Errorf("provenance not stored: %+v", p)
+	}
+
+	// The built-ins predate these columns and must still read cleanly.
+	plants, _ := s.ListPlants(ctx, owner)
+	for _, b := range plants {
+		if b.OwnerID == nil && (b.SourceURL != "" || b.Vendor != "") {
+			t.Errorf("built-in %q gained provenance from nowhere: %+v", b.Name, b)
+		}
+	}
+}
+
+// TestPlantingRejectsMismatchedLot — attributing a garlic planting to a tomato
+// lot would silently corrupt every remaining count downstream.
+func TestPlantingRejectsMismatchedLot(t *testing.T) {
+	s := newTestService(t, openConfig())
+	owner := seedUser(t, s, "[email protected]")
+	other := seedUser(t, s, "[email protected]")
+	g := seedGarden(t, s, owner)
+	bed := seedBed(t, s, owner, g.ID)
+	garlic := seedOwnPlant(t, s, owner, 15)
+	ctx := context.Background()
+
+	tomato, err := s.CreatePlant(ctx, owner, PlantInput{
+		Name: "Tomato", Category: domain.CategoryVegetable, SpacingCM: 45, Color: "#c0392b", Icon: "🍅",
+	})
+	if err != nil {
+		t.Fatalf("CreatePlant: %v", err)
+	}
+	tomatoLot := seedLot(t, s, owner, tomato.ID, 20, nil)
+
+	if _, err := s.CreatePlanting(ctx, owner, bed.ID, PlantingInput{
+		PlantID: garlic.ID, XCM: 0, YCM: 0, RadiusCM: 20, SeedLotID: &tomatoLot.ID,
+	}); !errors.Is(err, domain.ErrInvalidInput) {
+		t.Errorf("a garlic planting was attributed to a tomato lot (err=%v)", err)
+	}
+
+	// Someone else's lot is an invalid reference, not a leak of its existence.
+	othersPlant := seedOwnPlant(t, s, other, 15)
+	othersLot := seedLot(t, s, other, othersPlant.ID, 10, nil)
+	if _, err := s.CreatePlanting(ctx, owner, bed.ID, PlantingInput{
+		PlantID: garlic.ID, XCM: 0, YCM: 0, RadiusCM: 20, SeedLotID: &othersLot.ID,
+	}); !errors.Is(err, domain.ErrInvalidInput) {
+		t.Errorf("another user's lot was accepted (err=%v)", err)
+	}
+}
+
+// TestDeletingALotKeepsPlantingHistory — the plants really were in the ground,
+// whatever happened to the record of the packet.
+func TestDeletingALotKeepsPlantingHistory(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)
+	lot := seedLot(t, s, owner, plant.ID, 100, nil)
+	ctx := context.Background()
+
+	pl, err := s.CreatePlanting(ctx, owner, bed.ID, PlantingInput{
+		PlantID: plant.ID, XCM: 0, YCM: 0, RadiusCM: 20, SeedLotID: &lot.ID,
+	})
+	if err != nil {
+		t.Fatalf("CreatePlanting: %v", err)
+	}
+	if err := s.DeleteSeedLot(ctx, owner, lot.ID); err != nil {
+		t.Fatalf("DeleteSeedLot: %v", err)
+	}
+	survived, err := s.store.GetPlanting(ctx, pl.ID)
+	if err != nil {
+		t.Fatalf("planting was destroyed with its lot: %v", err)
+	}
+	if survived.SeedLotID != nil {
+		t.Errorf("seedLotId = %v, want null after the lot was deleted", *survived.SeedLotID)
+	}
+}
+
+// TestSeedLotVersionGuard — lots are version-guarded like every other mutable row.
+func TestSeedLotVersionGuard(t *testing.T) {
+	s := newTestService(t, openConfig())
+	owner := seedUser(t, s, "[email protected]")
+	plant := seedOwnPlant(t, s, owner, 15)
+	lot := seedLot(t, s, owner, plant.ID, 100, nil)
+	ctx := context.Background()
+
+	updated, err := s.UpdateSeedLot(ctx, owner, lot.ID, SeedLotPatch{Notes: strPtr("half used")}, lot.Version)
+	if err != nil {
+		t.Fatalf("UpdateSeedLot: %v", err)
+	}
+	if updated.Notes != "half used" || updated.Version != lot.Version+1 {
+		t.Errorf("unexpected update: %+v", updated)
+	}
+	// Stale version → conflict, carrying the current row.
+	current, err := s.UpdateSeedLot(ctx, owner, lot.ID, SeedLotPatch{Notes: strPtr("stale")}, lot.Version)
+	if !errors.Is(err, domain.ErrVersionConflict) {
+		t.Fatalf("err = %v, want ErrVersionConflict", err)
+	}
+	if current == nil || current.Notes != "half used" {
+		t.Errorf("conflict should carry the current row, got %+v", current)
+	}
+}
+
+// TestSeedLotUnitAndQuantityValidation
+func TestSeedLotUnitAndQuantityValidation(t *testing.T) {
+	s := newTestService(t, openConfig())
+	owner := seedUser(t, s, "[email protected]")
+	plant := seedOwnPlant(t, s, owner, 15)
+	ctx := context.Background()
+
+	if _, err := s.CreateSeedLot(ctx, owner, SeedLotInput{PlantID: plant.ID, Unit: "handfuls"}); !errors.Is(err, domain.ErrInvalidInput) {
+		t.Errorf("unknown unit accepted: %v", err)
+	}
+	if _, err := s.CreateSeedLot(ctx, owner, SeedLotInput{
+		PlantID: plant.ID, Unit: domain.UnitSeeds, Quantity: -1,
+	}); !errors.Is(err, domain.ErrInvalidInput) {
+		t.Errorf("negative quantity accepted: %v", err)
+	}
+	pct := 140.0
+	if _, err := s.CreateSeedLot(ctx, owner, SeedLotInput{
+		PlantID: plant.ID, Unit: domain.UnitSeeds, GerminationPct: &pct,
+	}); !errors.Is(err, domain.ErrInvalidInput) {
+		t.Errorf("140%% germination accepted: %v", err)
+	}
+	if _, err := s.CreateSeedLot(ctx, owner, SeedLotInput{
+		PlantID: plant.ID, Unit: domain.UnitSeeds, PurchasedAt: strPtr("not-a-date"),
+	}); !errors.Is(err, domain.ErrInvalidInput) {
+		t.Errorf("malformed purchase date accepted: %v", err)
+	}
+}
+
+func intPtr(v int) *int { return &v }