MVP M8: background detection — assumptions, risks, inconsistencies

The editor now runs Socrates' three Phase-0-validated detection prompts
against the live model, persists the findings, and surfaces them in a
new FindingsPanel beside the IssuesPanel. Click any finding to focus its
linked element across rail + diagram. Re-detect after model edits to
refresh against the new state.

apps/web/lib/llm/prompts/socrates
- detect-assumptions.md / detect-risks.md / detect-inconsistencies.md
  promoted verbatim from phase-0 (Phase 0 corpus validated them 10/10).

apps/web/lib/llm/detect.ts
- Three sequential detection passes (parallel was OOM-prone on 4B local
  models — Phase 0 lesson). Each pass uses the Phase 0 JSON schema with
  jsonObjectMode fallback + chatJSON repair-retry. Fail-soft per pass:
  one busted pass returns [] rather than blowing up the whole detect.
- post-validate strips hallucinated element refs (drops findings whose
  refs ALL fail to resolve; keeps findings with zero refs since some
  inconsistencies are genuinely about absences).

apps/web/prisma/schema.prisma
- Finding table: kind / text / linkedElementIds (JSON) / confidence /
  severity / validationCode / status / modelVersion / provider / model.
- ResearchFinding table reserved for the Tavily integration that comes
  next — schema in place so we don't have to migrate again.

apps/web/lib/db/repo.ts
- listOpenFindings(projectId), replaceFindings(...) — replaceFindings
  wipes prior open findings in a transaction and writes the new set so
  re-detect doesn't accumulate stale findings.

apps/web/app/api/projects/[projectId]/findings/route.ts
- GET returns persisted open findings.
- POST runs detect, persists, returns findings + meta (provider, model,
  durationMs, strippedRefs, droppedFindings).

apps/web/components/editor/FindingsPanel.tsx
- New panel, anchored bottom-right just left of IssuesPanel. Shows
  count summary (asm / risk / inc), detect / re-detect button, list
  grouped by kind (inconsistencies first, then risks, then assumptions),
  per-finding glyph + tag + severity + confidence + linked refs.
- Click a finding row → focus its first linked element via the same
  setFocusBlockId path the rail and IssuesPanel already use.
- "stale" indicator when the model version has advanced past the one the
  findings were detected against.

EditorShell wires version + projectId through to FindingsPanel.

Smoke-tested end-to-end: 12 findings returned (5 asm / 4 risk / 3 inc),
0 hallucinated refs stripped, ~37s on local gemma-4-e4b. Sample
assumption "students are willing to engage with an AI tutor that is
programmed to refuse providing complete solutions" — specific to
Aristotle's refusal_policy, not a generic startup truism.

Deferred to follow-ups: inline rail/diagram badges from findings,
auto-detect-on-save, Tavily research, experiment modal.

apps/web/prisma/schema.prisma

@@ -26,6 +26,7 @@ model Project {
   snapshots ModelSnapshot[]
   changes   ChangelogEntry[]
   threads   SocratesThread[]
+  findings  Finding[]
 }
 
 model ModelSnapshot {
@@ -87,3 +88,55 @@ model SocratesMessage {
 
   @@index([threadId, createdAt])
 }
+
+/// Background-detected finding (assumption / risk / inconsistency).
+/// Findings are scoped to the model version that produced them; on every
+/// detection run we delete the project's previous open findings and write
+/// the new set so we don't accumulate stale ones across model edits.
+model Finding {
+  id               String   @id @default(cuid())
+  projectId        String
+  /// "assumption" | "risk" | "inconsistency"
+  kind             String
+  text             String
+  /// JSON-encoded string[] of element ids this finding references.
+  linkedElementIds String
+  confidence       Float
+  /// Risks only: "low" | "medium" | "high"
+  severity         String?
+  /// Inconsistencies only: optional structural-rule code (S1, M2, T1, …)
+  validationCode   String?
+  /// Lifecycle: "open" | "dismissed" | "resolved"
+  status           String   @default("open")
+  /// Model version this finding was detected against.
+  modelVersion     Int
+  /// Provider + model that emitted the finding.
+  provider         String?
+  llmModel         String?
+  createdAt        DateTime @default(now())
+
+  project   Project           @relation(fields: [projectId], references: [id], onDelete: Cascade)
+  research  ResearchFinding[]
+
+  @@index([projectId, status])
+  @@index([projectId, kind])
+}
+
+/// Web research results from validating a finding via Tavily / similar.
+/// Deferred to a follow-up commit; schema is here so we don't have to
+/// migrate again later.
+model ResearchFinding {
+  id        String   @id @default(cuid())
+  findingId String
+  query     String
+  url       String
+  title     String?
+  snippet   String?
+  /// "supports" | "contradicts" | "neutral"
+  stance    String   @default("neutral")
+  createdAt DateTime @default(now())
+
+  finding Finding @relation(fields: [findingId], references: [id], onDelete: Cascade)
+
+  @@index([findingId])
+}