Merge remote-tracking branch 'origin/master' into xtr/identified-immutable-messages

# Conflicts:
#	.agents/notes/implemented/architecture/2026-07-24-separate-context-injection-from-turn-execution.i18n.yaml
#	docs/cordis-catalog/services.md
#	docs/core-data-structures/core.i18n.yaml
#	docs/core-data-structures/session.i18n.yaml
#	docs/event-producer-consumer.md
#	docs/persistence-catalog.md
#	packages/core/session/README.i18n.yaml
#	packages/session-title/session-title/tests/persistence.spec.ts

packages/compact/compact/tests/invariant.spec.ts

@@ -1,6 +1,6 @@
 import { describe, expect, it } from 'vitest'
 import { Context } from 'cordis'
-import SessionStore from '@deepseek-ai/dsh-session'
+import SessionStore, { Session, SessionId } from '@deepseek-ai/dsh-session'
 import * as CompactInvariant from '@deepseek-ai/dsh-compact/invariant'
 import InvariantService from '@deepseek-ai/dsh-invariants'
 
@@ -22,15 +22,21 @@ const summary = (overrides: Record<string, unknown> = {}) => ({
   ...overrides,
 })
 
+function startTurn(session: ReturnType<Context['sessions']['create']>, turn = 1): void {
+  session.append('turn/start', { turn, trigger: { kind: 'message', source: { kind: 'user' } } })
+}
+
 describe('compaction invariants', () => {
   it('accepts successful and failed compaction lifecycles', async () => {
     const ctx = await setup()
     const success = ctx.sessions.create()
+    startTurn(success)
     success.append('compact/start', { turn: 1 })
     success.append('compact/summary', summary())
     success.append('compact/end', { turn: 1 })
 
     const failed = ctx.sessions.create()
+    startTurn(failed, 2)
     failed.append('compact/start', { turn: 2 })
     failed.append('compact/end', { turn: 2, error: 'provider failed' })
   })
@@ -40,13 +46,68 @@ describe('compaction invariants', () => {
     await ctx.plugin(SessionStore)
     const session = ctx.sessions.create()
     session.append('turn/start', { turn: 1, trigger: { kind: 'message', source: { kind: 'user' } } })
-    session.append('compact/start', { turn: 3 })
+    session.append('compact/start', { turn: 1 })
     await ctx.plugin(InvariantService)
     await ctx.plugin(CompactInvariant)
-    expect(() => session.append('compact/end', { turn: 3, error: 'resume failed' })).not.toThrow()
+    expect(() => session.append('compact/end', { turn: 1, error: 'resume failed' })).not.toThrow()
     session.append('turn/end', { turn: 1, reason: { kind: 'completed' } })
   })
 
+  it('adopts a bare session and ignores unrelated committed events', async () => {
+    const ctx = await setup()
+    const session = new Session(SessionId('bare-compaction-session'))
+    expect(() => {
+      ctx.emit('session/event', session, {
+        type: 'turn/start', seq: 0, time: 0,
+        data: { turn: 1, trigger: { kind: 'message', source: { kind: 'user' } } },
+      })
+      ctx.emit('session/event', session, {
+        type: 'step/start', seq: 1, time: 1, data: { turn: 1, step: 1 },
+      })
+      ctx.emit('session/event', session, {
+        type: 'compact/start', seq: 2, time: 2, data: { turn: 1 },
+      })
+    }).not.toThrow()
+  })
+
+  it('rejects compaction outside or for a different open turn', async () => {
+    const ctx = await setup()
+    const session = ctx.sessions.create()
+    expect(() => session.append('compact/start', { turn: 1 })).toThrow(/outside any open turn/)
+    startTurn(session)
+    expect(() => session.append('compact/start', { turn: 2 })).toThrow(/but open turn is 1/)
+  })
+
+  it('rejects an unenclosed compaction event when replaying an existing session', async () => {
+    const ctx = new Context()
+    await ctx.plugin(SessionStore)
+    const session = ctx.sessions.create()
+    startTurn(session)
+    session.append('turn/end', { turn: 1, reason: { kind: 'completed' } })
+    session.append('compact/start', { turn: 1 })
+    await ctx.plugin(InvariantService)
+    await expect(ctx.plugin(CompactInvariant).then(() => undefined)).rejects.toThrow(/outside any open turn/)
+  })
+
+  it('rejects an open compaction that crosses into another turn', async () => {
+    const ctx = await setup()
+    const summarySession = ctx.sessions.create()
+    startTurn(summarySession)
+    summarySession.append('compact/start', { turn: 1 })
+    summarySession.append('turn/end', { turn: 1, reason: { kind: 'completed' } })
+    startTurn(summarySession, 2)
+    expect(() => summarySession.append('compact/summary', summary()))
+      .toThrow(/belongs to turn 1 but open turn is 2/)
+
+    const endSession = ctx.sessions.create()
+    startTurn(endSession)
+    endSession.append('compact/start', { turn: 1 })
+    endSession.append('turn/end', { turn: 1, reason: { kind: 'completed' } })
+    startTurn(endSession, 2)
+    expect(() => endSession.append('compact/end', { turn: 1, error: 'late' }))
+      .toThrow(/names turn 1 but open turn is 2/)
+  })
+
   it.each([
     ['summary without start', (session: ReturnType<Context['sessions']['create']>) => {
       session.append('compact/summary', summary())
@@ -85,6 +146,8 @@ describe('compaction invariants', () => {
     }, /requires one compact\/summary/],
   ])('rejects %s', async (_name, action, message) => {
     const ctx = await setup()
-    expect(() => { action(ctx.sessions.create()) }).toThrow(message)
+    const session = ctx.sessions.create()
+    startTurn(session)
+    expect(() => { action(session) }).toThrow(message)
   })
 })