fix(2137): skip worktree isolation when .gitmodules detected (#2144)

* feat(sdk): add typed query foundation and gsd-sdk query (Phase 1)

Add sdk/src/query registry and handlers with tests, GSDQueryError, CLI query wiring, and supporting type/tool-scoping hooks. Update CHANGELOG. Vitest 4 constructor mock fixes in milestone-runner tests.

Made-with: Cursor

* fix(2137): skip worktree isolation when .gitmodules detected

When a project contains git submodules, worktree isolation cannot
correctly handle submodule commits — three separate gaps exist in
worktree setup, executor commit protocol, and merge-back. Rather
than patch each gap individually, detect .gitmodules at phase start
and fall back to sequential execution, which handles submodules
transparently (Option B).

Affected workflows: execute-phase.md, quick.md

---------

Co-authored-by: David Sienkowski <dave@sienkowski.com>

get-shit-done/workflows/execute-phase.md

@@ -82,6 +82,15 @@ Read worktree config:
 USE_WORKTREES=$(node "$HOME/.claude/get-shit-done/bin/gsd-tools.cjs" config-get workflow.use_worktrees 2>/dev/null || echo "true")
 ```
 
+If the project uses git submodules, worktree isolation is skipped regardless of the `workflow.use_worktrees` config — the executor commit protocol cannot correctly handle submodule commits inside isolated worktrees. Sequential execution handles submodules transparently.
+
+```bash
+if [ -f .gitmodules ]; then
+  echo "[worktree] Submodule project detected (.gitmodules exists) — falling back to sequential execution"
+  USE_WORKTREES=false
+fi
+```
+
 When `USE_WORKTREES` is `false`, all executor agents run without `isolation="worktree"` — they execute sequentially on the main working tree instead of in parallel worktrees.
 
 Read context window size for adaptive prompt enrichment: