Merge remote-tracking branch 'origin/master' into codex/enforce-tool-cancellation

# Conflicts:
#	docs/event-producer-consumer.md
#	examples/acp-agent/tests/snapshots/bash-spill/session.jsonl
#	examples/acp-agent/tests/snapshots/escalation-approved/session.jsonl
#	examples/acp-agent/tests/snapshots/escalation-rejected/session.jsonl
#	examples/acp-agent/tests/snapshots/fs-escalation-approved/session.jsonl
#	examples/acp-agent/tests/snapshots/hook-cc-pretool-ask/session.jsonl
#	packages/context/workspace-context/tests/workspace-context.spec.ts
#	packages/core/agent/src/index.ts
#	packages/support/invariants/tests/invariants.spec.ts
#	packages/ui/acp/src/index.ts
#	packages/ui/tui/tests/harness.ts
#	packages/ui/tui/tests/tui.spec.ts

packages/hooks/hook-protocol/src/invariant.ts

@@ -0,0 +1,101 @@
+/** Package-owned hook provenance-stream invariants. @module @deepseek-ai/dsh-hook-protocol/invariant */
+
+import type { Context } from 'cordis'
+import type { Session, SessionEvent } from '@deepseek-ai/dsh-session'
+import type { InvariantFailure, InvariantInstaller } from '@deepseek-ai/dsh-invariants'
+import type {} from './types.ts'
+
+const PACKAGE_NAME = '@deepseek-ai/dsh-hook-protocol'
+
+/** Cordis companion plugin name. */
+export const name = 'hook-protocol-invariant'
+/** Service required before the companion can reserve package ownership. */
+export const inject = ['invariants']
+
+interface HookTransition {
+  key: string
+  delta: 1 | -1
+}
+
+/** Correlation key shared by an invoked/result pair. */
+function hookKey(data: { turn: number; point: string; handlerId: string }): string {
+  return `${data.turn}\0${data.point}\0${data.handlerId}`
+}
+
+/** Validate one hook event against committed pending invocations. */
+function validateHookEvent(
+  pending: ReadonlyMap<string, number>,
+  event: SessionEvent,
+  fail: InvariantFailure,
+): HookTransition | undefined {
+  if (event.type === 'hook/invoked') {
+    if (event.data.point.length === 0 || event.data.handlerId.length === 0) {
+      fail('hook/invoked point and handlerId must be non-empty')
+    }
+    const dialect: string = event.data.dialect
+    if (dialect !== 'claude' && dialect !== 'codex') {
+      fail(`hook/invoked carries unknown dialect ${JSON.stringify(dialect)}`)
+    }
+    return { key: hookKey(event.data), delta: 1 }
+  }
+  if (event.type !== 'hook/result') return undefined
+  const key = hookKey(event.data)
+  if ((pending.get(key) ?? 0) === 0) {
+    fail(`hook/result has no matching hook/invoked for ${JSON.stringify(event.data.handlerId)}`)
+  }
+  if (!Number.isFinite(event.data.durationMs) || event.data.durationMs < 0) {
+    fail('hook/result durationMs must be a non-negative finite number')
+  }
+  return { key, delta: -1 }
+}
+
+/** Apply one committed hook-pair transition. */
+function applyHookTransition(pending: Map<string, number>, transition: HookTransition): void {
+  const next = (pending.get(transition.key) ?? 0) + transition.delta
+  if (next === 0) pending.delete(transition.key)
+  else pending.set(transition.key, next)
+}
+
+/** Install hook invoked/result pairing checks. */
+// Event owners keep precommit staging local so their vocabularies never move into a central helper.
+/* jscpd:ignore-start */
+const install: InvariantInstaller = Object.assign((ctx: Context, fail: InvariantFailure) => {
+  const traces = new WeakMap<Session, Map<string, number>>()
+  const staged = new WeakMap<SessionEvent, { session: Session; transition: HookTransition }>()
+  const seed = (session: Session): Map<string, number> => {
+    const pending = new Map<string, number>()
+    traces.set(session, pending)
+    for (const event of session.events) {
+      const transition = validateHookEvent(pending, event, fail)
+      if (transition !== undefined) applyHookTransition(pending, transition)
+    }
+    return pending
+  }
+  const traceFor = (session: Session): Map<string, number> => traces.get(session) ?? seed(session)
+
+  for (const session of ctx.sessions.list()) seed(session)
+  ctx.on('session/created', (session) => { seed(session) }, { global: true })
+  ctx.on('session/event', (session, event) => {
+    if (event.type !== 'hook/invoked' && event.type !== 'hook/result') return
+    const candidate = staged.get(event)
+    /* v8 ignore next -- internal/dispatch stages every hook provenance event */
+    if (candidate === undefined || candidate.session !== session) return fail('hook event published without pre-commit validation')
+    staged.delete(event)
+    applyHookTransition(traceFor(session), candidate.transition)
+  }, { global: true })
+  ctx.on('internal/dispatch', (_mode, eventName, args) => {
+    if (eventName !== 'session/event') return
+    const [session, event] = args as [Session, SessionEvent]
+    const transition = validateHookEvent(traceFor(session), event, fail)
+    if (transition !== undefined) staged.set(event, { session, transition })
+  }, { global: true })
+}, { inject: ['sessions'] })
+/* jscpd:ignore-end */
+
+/**
+ * Register the hook-protocol invariant companion.
+ * @param ctx - Cordis context carrying the invariant service.
+ * @returns the installed registration's disposer after setup succeeds.
+ */
+export const apply = (ctx: Context): Promise<() => void> =>
+  Promise.resolve(ctx.invariants.register(PACKAGE_NAME, install))