refactor: remove dead code and narrow internal exports (knip sweep)

Knip-driven cleanup. All changes verified with tsc --noEmit, lint, and
build.

Removed (zero consumers):
- VERIFICATION_PROMPT constant + its barrel re-export
- createInitialOrchestratorPersistState factory
- transcriptWatcher singleton export
- createAnsiPatternFull / createAnsiPatternSimple factories
- TimerInfo interface + unused AiCheckResult/AiPlanCheckResult imports
  in respawn-controller.ts
- 35 unused Zod z.infer \`*Input\` types in schemas.ts
- Dead re-exports: SessionMode from session.ts, AuthSessionRecord from
  web/ports/index.ts, EnhancedPlanTask/CheckpointReview from
  ralph-tracker.ts, 7 unused entries in utils/index.ts
- 14 event/config interfaces that lived only as JSDoc hints (no TS type
  position usage): Session/Respawn/RalphLoop/RalphTracker/
  SessionManager/SessionAutoOps/Subagent/TaskQueue/TaskTracker/
  TranscriptWatcher/Image/OrchestratorLoop Events + RespawnPreset +
  SessionOutput

Narrowed to module scope (kept but no longer exported):
- buildPermissionArgs in session-cli-builder.ts
- 28 type/interface declarations used only within their own file:
  Ai{Idle,Plan}Check{Config,State}, BashToolParser{Events,Config},
  FileStream/CreateStream{Options,Result}, PlanSubagentEvent,
  SubagentCallback, RalphLoopConfig, RalphLoop{Events,Options},
  ActiveTimerInfo, DetectionStatus, ActionLogEntry, AutoOpsCallbacks,
  TunnelStatus, Timer/LRUMap/StaleExpirationMap Options, AuthState,
  SessionListenerDeps, SseStreamManagerDeps, and 8 more

Docs: CLAUDE.md advice for global-regex `lastIndex` now points to the
remaining `execPattern()` helper instead of the deleted factories.

Knip delta: unused files 42→0, unused exports 161→16, unused types 92→0.
The 16 remaining exports are a mobile-test helper toolkit intentionally
kept for upcoming tests.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/file-stream-manager.ts

@@ -48,7 +48,7 @@ const STREAM_INACTIVITY_TIMEOUT_MS = INACTIVITY_TIMEOUT_MS;
 /**
  * Represents an active file stream.
  */
-export interface FileStream {
+interface FileStream {
   /** Unique stream identifier */
   id: string;
   /** Session this stream belongs to */
@@ -74,7 +74,7 @@ export interface FileStream {
 /**
  * Options for creating a file stream.
  */
-export interface CreateStreamOptions {
+interface CreateStreamOptions {
   /** Session ID requesting the stream */
   sessionId: string;
   /** Path to the file to stream */
@@ -94,7 +94,7 @@ export interface CreateStreamOptions {
 /**
  * Result of creating a stream.
  */
-export interface CreateStreamResult {
+interface CreateStreamResult {
   success: boolean;
   streamId?: string;
   error?: string;