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/instance_settings.go

@@ -100,6 +100,13 @@ func (s *Service) EffectiveAgent(ctx context.Context) (EffectiveAgent, error) {
 	if err != nil {
 		return EffectiveAgent{}, err
 	}
+	return s.agentOver(st), nil
+}
+
+// agentOver layers a settings row over the env-derived agent defaults. Split out
+// so EffectiveConfig can resolve agent AND vision from a single row read instead
+// of fetching the same one-row table twice.
+func (s *Service) agentOver(st *domain.InstanceSettings) EffectiveAgent {
 	eff := EffectiveAgent{
 		Model:   s.cfg.Agent.Model,
 		Enabled: s.cfg.Agent.Enabled,
@@ -111,7 +118,7 @@ func (s *Service) EffectiveAgent(ctx context.Context) (EffectiveAgent, error) {
 	if st.AgentEnabled != nil {
 		eff.Enabled = *st.AgentEnabled
 	}
-	return eff, nil
+	return eff
 }
 
 // EffectiveVision resolves the vision configuration in force for seed-packet
@@ -133,6 +140,12 @@ func (s *Service) EffectiveVision(ctx context.Context) (EffectiveVision, error)
 	if err != nil {
 		return EffectiveVision{}, err
 	}
+	return s.visionOver(st), nil
+}
+
+// visionOver layers a settings row over the env-derived vision defaults. See
+// agentOver for why this is split from EffectiveVision.
+func (s *Service) visionOver(st *domain.InstanceSettings) EffectiveVision {
 	eff := EffectiveVision{
 		Model:  s.cfg.Agent.VisionModel,
 		APIKey: s.cfg.Agent.OllamaCloudAPIKey,
@@ -140,5 +153,16 @@ func (s *Service) EffectiveVision(ctx context.Context) (EffectiveVision, error)
 	if st.VisionModel != "" {
 		eff.Model = st.VisionModel
 	}
-	return eff, nil
+	return eff
+}
+
+// EffectiveConfig resolves the agent AND vision configuration from ONE settings
+// read, for callers (the settings view) that need both — the single-row table
+// would otherwise be fetched twice for one response.
+func (s *Service) EffectiveConfig(ctx context.Context) (EffectiveAgent, EffectiveVision, error) {
+	st, err := s.store.GetInstanceSettings(ctx)
+	if err != nil {
+		return EffectiveAgent{}, EffectiveVision{}, err
+	}
+	return s.agentOver(st), s.visionOver(st), nil
 }