Address seed-packet review: 413 mapping, deadline, rollback, dedup

Gadfly findings on #94, the real ones:

- scanSeedPacket extends only the READ deadline; a slow upload + a live
  vision call runs past the server's absolute 30s WriteTimeout and the
  successful response is silently dropped (the #78 failure mode). Extend
  the write deadline too (scanWriteTimeout).
- An oversized upload tripping MaxBytesReader was mapped to 400; it's 413.
  Detect *http.MaxBytesError and report IMAGE_TOO_LARGE.
- Split imagenorm error mapping: ErrTooLarge->413, ErrUnsupported->400,
  genuine read/encode faults (and a failed file.Open)->500, not 400.
- CreateFromPacket discarded the plant it created when the lot then
  failed, contradicting its own doc. Roll the new plant back instead so
  the confirm is all-or-nothing (a fresh plant has no lots/plantings, so
  the delete is safe; log-and-continue on cleanup failure).
- Dedup: packetLotRequest and seedLotCreateRequest shared every lot
  field. Extract a seedLotFields base both use. validCategory now reuses
  plantCategories. EffectiveConfig resolves agent+vision from one
  settings-row read instead of two.
- capabilities swallowed an EffectiveVision error silently; log it.
- vision test hand-copied Extract's body (drift risk). Split generate()
  out of Extract so the hermetic test drives the real request builder.

Tests: rollback-on-lot-failure (service), oversized->413 (api).

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

internal/service/seed_packet.go

@@ -2,6 +2,7 @@ package service
 
 import (
 	"context"
+	"log/slog"
 	"sort"
 	"strings"
 
@@ -85,14 +86,13 @@ func suggestedName(p vision.SeedPacket) string {
 }
 
 // validCategory returns the packet's category if it's one pansy knows, else "".
+// It reuses plantCategories — the same set CreatePlant validates against — so a
+// new category can't be accepted by one path and rejected by the other.
 func validCategory(c string) string {
-	switch c {
-	case domain.CategoryVegetable, domain.CategoryHerb, domain.CategoryFlower,
-		domain.CategoryFruit, domain.CategoryTreeShrub, domain.CategoryCover:
+	if _, ok := plantCategories[c]; ok {
 		return c
-	default:
-		return ""
 	}
+	return ""
 }
 
 // matchPlants ranks existing plants the packet might already be, best first.
@@ -179,10 +179,12 @@ type PacketResult struct {
 // history — plants and lots are catalog/inventory, created directly — so there is
 // no change set to wrap; the two creations just happen in sequence.
 //
-// If a new plant is created but the lot then fails, the plant is left behind
-// rather than rolled back: a stray catalog entry is harmless and editable,
-// whereas silently discarding a variety the user just confirmed is worse. The
-// caller sees the error and can retry the lot against the now-existing plant.
+// If a new plant is created but the lot then fails, the plant is rolled back so
+// the confirm is all-or-nothing. Otherwise a bad lot (say, an invalid unit) would
+// strand a half-made catalog entry the user never asked for on its own, and the
+// error return gives the HTTP caller no handle to it. A just-created plant has no
+// plantings or lots yet, so the delete is safe; if it somehow can't be undone we
+// log and still surface the original lot error, not the cleanup one.
 func (s *Service) CreateFromPacket(ctx context.Context, actorID int64, in PacketConfirm) (*PacketResult, error) {
 	hasID, hasNew := in.PlantID != nil, in.NewPlant != nil
 	if hasID == hasNew {
@@ -211,6 +213,13 @@ func (s *Service) CreateFromPacket(ctx context.Context, actorID int64, in Packet
 	lotIn.PlantID = res.Plant.ID
 	lot, err := s.CreateSeedLot(ctx, actorID, lotIn)
 	if err != nil {
+		if res.PlantIsNew {
+			// Roll back the plant we just made for this confirm; keep the lot error.
+			if delErr := s.DeletePlant(ctx, actorID, res.Plant.ID); delErr != nil {
+				slog.Error("service: could not roll back plant after packet lot failed",
+					"error", delErr, "plant", res.Plant.ID)
+			}
+		}
 		return nil, err
 	}
 	res.Lot = lot