feat(plugin): local scene-memory reader (tdai_read_local) + guarded read_cos

[YOMXXX]

Closes #762.

Problem

For COS-less local deployments the scene-detail read tool tdai_read_cos is the only way to open scene-memory files, but it always fails without COS:

• format.ts injects only the scene path index, and the guide advertises tdai_read_cos
• index.ts registers tdai_read_cos unconditionally — a tool that is guaranteed to fail, wasting AI call budget

Result: the AI "knows a scene exists but can't recall the details".

Change

Commit 1 — feat(plugin): add tdai_read_local tool with path-safety checks

• New src/tools/read-local.ts: reads a local file by relative path from a configured root
• Security: rejects empty/absolute (POSIX + Windows drive-letter/UNC) and any .. traversal, plus a resolve+relative containment check (defense-in-depth)

Commit 2 — feat(plugin): guard scene-detail tools by storage.localDir

• openclaw.plugin.json: new storage.localDir config field
• index.ts: registers exactly one read tool — tdai_read_local when storage.localDir is set (local mode), otherwise tdai_read_cos (default COS mode). No longer registers a tool that is guaranteed to fail.
• format.ts / recall.ts: the memory-tools guide and Scene Navigation hint are now dynamic, guiding the tool that is actually registered (tdai_read_cos / tdai_read_local, or neither)
• README (CN/EN): document storage.localDir

Tests

vitest added to openclaw-plugin (first tests for this package):

• src/tools/read-local.test.ts — 9 tests: path-safety (traversal, absolute, drive-letter, UNC, blank) + local reads (nested block, missing file, rejected paths)
• src/format.test.ts — 4 tests: guide/hint reflect readTool (local / default cos / none)

npm test: 2 files, 13 tests, all passing. npm run build (tsc) passes.

Behavior summary

storage.localDir	registered read tool	prompt guide
unset (default)	tdai_read_cos	tdai_read_cos
set to a local dir	tdai_read_local	tdai_read_local
(both missing)	—	no read-tool guidance

[Maxwell-Code07]

Thanks for your attention! We will schedule an internal review as soon as possible.