refactor: implement in-process worker architecture for hooks (#722)

* fix: stop generating empty CLAUDE.md files

- Return empty string instead of "No recent activity" when no observations exist
- Skip writing CLAUDE.md files when formatted content is empty
- Remove redundant "auto-generated by claude-mem" HTML comment
- Clean up 98 existing empty CLAUDE.md files across the codebase
- Update tests to expect empty string for empty input

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

* build assets

* refactor: implement in-process worker architecture for hooks

Replaces spawn-based worker startup with in-process architecture:
- Hook processes now become the worker when port 37777 is free
- Eliminates Windows spawn issues (NO SPAWN rule)
- SessionStart chains: smart-install && stop && context

Key changes:
- worker-service.ts: hook case starts WorkerService in-process
- hook-command.ts: skipExit option prevents process.exit() when hosting worker
- hooks.json: single chained command replaces separate start/hook commands
- worker-utils.ts: ensureWorkerRunning() returns boolean, doesn't block
- handlers: graceful fallback when worker unavailable

All 761 tests pass. Manual verification confirms hook stays alive as worker.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

* context

* a

* MAESTRO: Mark PR #722 test verification task complete

All 797 tests passed (3 skipped, 0 failed) after merge conflict resolution.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

* MAESTRO: Mark PR #722 build verification task complete

* MAESTRO: Mark PR #722 code review task complete

Code review verified:
- worker-service.ts hook case starts WorkerService in-process
- hook-command.ts has skipExit option
- hooks.json uses single chained command
- worker-utils.ts ensureWorkerRunning() returns boolean

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

* MAESTRO: Mark PR #722 conflict resolution push task complete

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

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Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>

src/cli/handlers/summarize.ts

@@ -10,11 +10,16 @@ import type { EventHandler, NormalizedHookInput, HookResult } from '../types.js'
 import { ensureWorkerRunning, getWorkerPort } from '../../shared/worker-utils.js';
 import { logger } from '../../utils/logger.js';
 import { extractLastMessage } from '../../shared/transcript-parser.js';
+import { HOOK_EXIT_CODES } from '../../shared/hook-constants.js';
 
 export const summarizeHandler: EventHandler = {
   async execute(input: NormalizedHookInput): Promise<HookResult> {
     // Ensure worker is running before any other logic
-    await ensureWorkerRunning();
+    const workerReady = await ensureWorkerRunning();
+    if (!workerReady) {
+      // Worker not available - skip summary gracefully
+      return { continue: true, suppressOutput: true, exitCode: HOOK_EXIT_CODES.SUCCESS };
+    }
 
     const { sessionId, transcriptPath } = input;