feat(sdk): Phase 1 typed query foundation (gsd-sdk query) (#2118)

* 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

* chore: gitignore .cursor for local-only Cursor assets

Made-with: Cursor

* fix(sdk): harden query layer for PR review (paths, locks, CLI, ReDoS)

- resolvePathUnderProject: realpath + relative containment for frontmatter and key_links

- commitToSubrepo: path checks + sanitizeCommitMessage

- statePlannedPhase: readModifyWriteStateMd (lock); MUTATION_COMMANDS + events

- key_links: regexForKeyLinkPattern length/ReDoS guard; phase dirs: reject .. and separators

- gsd-sdk: strip --pick before parseArgs; strict parser; QueryRegistry.commands()

- progress: static GSDError import; tests updated

Made-with: Cursor

* feat(sdk): query follow-up — tests, QUERY-HANDLERS, registry, locks, intel depth

Made-with: Cursor

* docs(sdk): use ASCII punctuation in QUERY-HANDLERS.md

Made-with: Cursor

sdk/src/query/frontmatter-mutation.test.ts

@@ -232,3 +232,28 @@ describe('frontmatterValidate', () => {
     expect(FRONTMATTER_SCHEMAS).toHaveProperty('verification');
   });
 });
+
+// ─── Round-trip (extract → reconstruct → splice) ───────────────────────────
+
+describe('frontmatter round-trip', () => {
+  it('preserves scalar and list fields through extract + splice', () => {
+    const original = `---
+phase: "01"
+plan: "02"
+type: execute
+wave: 1
+depends_on: []
+tags: [a, b]
+---
+# Title
+`;
+    const fm = extractFrontmatter(original) as Record<string, unknown>;
+    const spliced = spliceFrontmatter('# Title\n', fm);
+    expect(spliced.startsWith('---\n')).toBe(true);
+    const round = extractFrontmatter(spliced) as Record<string, unknown>;
+    expect(String(round.phase)).toBe('01');
+    // YAML may round-trip wave as number or string depending on parser output
+    expect(Number(round.wave)).toBe(1);
+    expect(Array.isArray(round.tags)).toBe(true);
+  });
+});