refactor: wave 1 - extract leaf modules, rename catch-all files, split index.ts hooks

- Split 25+ index.ts files into hook.ts + extracted modules
- Rename all catch-all utils.ts/helpers.ts to domain-specific names
- Split src/tools/lsp/ into ~15 focused modules
- Split src/tools/delegate-task/ into ~18 focused modules
- Separate shared types from implementation
- 155 files changed, 60+ new files created
- All typecheck clean, 61 tests pass

src/tools/session-manager/utils.test.ts

@@ -6,7 +6,7 @@ import {
   formatSearchResults,
   filterSessionsByDate,
   searchInSession,
-} from "./utils"
+} from "./session-formatter"
 import type { SessionInfo, SessionMessage, SearchResult } from "./types"
 
 describe("session-manager utils", () => {