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/session.ts

@@ -154,63 +154,6 @@ export interface ClaudeMessage {
  * Event signatures emitted by the Session class.
  * Subscribe using `session.on('eventName', handler)`.
  */
-export interface SessionEvents {
-  /** Processed text output (ANSI stripped) */
-  output: (data: string) => void;
-  /** Parsed JSON message from Claude CLI */
-  message: (msg: ClaudeMessage) => void;
-  /** Error output from the session */
-  error: (data: string) => void;
-  /** Session process exited */
-  exit: (code: number | null) => void;
-  /** One-shot prompt completed with result and cost */
-  completion: (result: string, cost: number) => void;
-  /** Raw terminal data (includes ANSI codes) */
-  terminal: (data: string) => void;
-  /** Signal to clear terminal display (after mux attach) */
-  clearTerminal: () => void;
-  /** New background task started */
-  taskCreated: (task: BackgroundTask) => void;
-  /** Background task status changed */
-  taskUpdated: (task: BackgroundTask) => void;
-  /** Background task finished successfully */
-  taskCompleted: (task: BackgroundTask) => void;
-  /** Background task failed with error */
-  taskFailed: (task: BackgroundTask, error: string) => void;
-  /** Auto-clear triggered due to token threshold */
-  autoClear: (data: { tokens: number; threshold: number }) => void;
-  /** Auto-compact triggered due to token threshold */
-  autoCompact: (data: { tokens: number; threshold: number; prompt?: string }) => void;
-  /** Ralph loop state changed */
-  ralphLoopUpdate: (state: RalphTrackerState) => void;
-  /** Ralph todo list updated */
-  ralphTodoUpdate: (todos: RalphTodoItem[]) => void;
-  /** Ralph completion phrase detected */
-  ralphCompletionDetected: (phrase: string) => void;
-  /** RALPH_STATUS block detected */
-  ralphStatusBlockDetected: (block: import('./types.js').RalphStatusBlock) => void;
-  /** Circuit breaker state changed */
-  ralphCircuitBreakerUpdate: (status: import('./types.js').CircuitBreakerStatus) => void;
-  /** Dual-condition exit gate met */
-  ralphExitGateMet: (data: { completionIndicators: number; exitSignal: boolean }) => void;
-  /** Bash tool with file paths started */
-  bashToolStart: (tool: ActiveBashTool) => void;
-  /** Bash tool completed */
-  bashToolEnd: (tool: ActiveBashTool) => void;
-  /** Active Bash tools list updated */
-  bashToolsUpdate: (tools: ActiveBashTool[]) => void;
-  /** CLI info (version, model, account) updated */
-  cliInfoUpdated: (info: {
-    version: string | null;
-    model: string | null;
-    accountType: string | null;
-    latestVersion: string | null;
-  }) => void;
-}
-
-// SessionMode is imported from types.ts (single source of truth)
-// Re-export for backwards compatibility with any external consumers
-export type { SessionMode } from './types.js';
 
 /**
  * Core session class that wraps a PTY process running Claude CLI or a shell.