fix: stabilize LocalText and error contracts (0.13.1)

[linnnn89]

LocalText previously returned declarations from comments and strings and omitted TSX/JSX files. This patch masks supported non-code regions before declaration matching, preserves source lines/signatures, invalidates old caches, and reports uncertain lexical boundaries as incomplete and uncached. The existing C# masker is shared with UI mapping; script/JSX parsing remains deliberately limited text analysis.

The E4 contract suite now covers partial trash moves, workspace recovery and UI serialization and runs in Node 22 CI. Unknown tools return JSON-RPC -32602 during normal admission; known tool errors keep domain details and matching JSON/structuredContent. Impact returns one JSON text block with all evidence and formattedReport retained, including the alias. Consumers of the former second Markdown block must read formattedReport.

Validation:

• Full check: 317 passed, 1 optional TavernDesk integration skipped, 0 failed; typecheck, locked builds, production stdio and complete delivery verification passed.
• Desktop fixture: 35/35. Real Roslyn Host: 58 scenarios. Real Roslyn MCP: 19 scenarios. E4: 16 scenarios.
• RED/GREEN regressions cover false declarations, TSX/JSX, uncertain input, old caches, cancellation and protocol/output contracts. Author review added and fixed regex literals following blocks.
• Same fixture impact text reduced from 3194 to 2511 UTF-16 characters; no token or broad performance claim.
• 77 documentation links checked; version, repository Skill and plans aligned to 0.13.1.

Actual Codex-client Roslyn acceptance is explicitly deferred by the user. Client configuration and installed Skill were not changed; no new dependency was introduced. Text references and complex syntax remain heuristic. Detailed local receipts and failed-attempt history are recorded in docs/codex_worklog.md.