Merge remote-tracking branch 'origin/master' into worktree/semantic-session-checkpoints

# Conflicts:
#	docs/architecture.md
#	docs/event-producer-consumer.md
#	examples/acp-agent/tests/snapshots/cancel-tool-calls/session.jsonl
#	packages/core/agent-loop/README.md
#	packages/core/agent-loop/src/loop.ts
#	packages/core/agent-loop/tests/cancel.spec.ts

packages/examples/tui-demo/src/index.ts

@@ -46,6 +46,8 @@ export interface Config {
   tools?: ToolsConfig
   /** DeepSeek Harness home directory exposed to bash and used for local skill discovery. */
   dshHome?: string
+  /** Fallback session-title limits forwarded through agent-spine-demo. */
+  sessionTitle?: NonNullable<agentCore.Config['sessionTitle']>
   /** Directory the JSONL session backend writes under. Defaults to `./.sessions`. */
   persistenceRoot?: string
   /** JSONL artifact encoding; defaults to checksummed Zstandard frames. */
@@ -80,6 +82,7 @@ export const Config: z<Config> = z.object({
   toolOrder: z.array(z.string()).default(undefined as unknown as string[]),
   tools: ToolRegistry.Config,
   dshHome: z.string(),
+  sessionTitle: agentCore.SessionTitleConfigSchema,
   persistenceRoot: z.string().default(DEFAULT_PERSISTENCE_ROOT),
   persistenceCompression: JsonlCompressionSchema,
   welcome: z.string().default(DEFAULT_WELCOME),