feat(plugins): expose indexed workspace symbol search (#2040)

Closes #1944

API 1.3 lets a plugin search the IDE's workspace symbol index. Results are limited to paths the plugin may read under its `project.read` grant (external content roots and symlink aliases excluded), the search honours the call's cancellation and deadline including lock waits, and ranges use UTF-16. Incremental index updates no longer publish symlink-ancestor aliases. Verified on macOS with the test fixture.

Co-authored-by: arnaud-ritti <[email protected]>

plugins/official/string-tools/dist/plugin.wasm.sources

@@ -1 +1 @@
-2504128882832c282d627946668f10603fe4b165dca8f12a49131934d1a5c09d
+10c214d40a6b43bb8b850bfe6d97c1a360ed748b5e95645354b3317806d7a538