chore(#191): retire the gsd-sdk shim — route everything at gsd-tools (#522)

* chore(#191): migrate gsd-sdk query call sites to gsd-tools query

Retiring the gsd-sdk shim. gsd-tools.cjs already accepts `query` as a
meta-prefix (gsd-tools query <command>), so this is a behavior-preserving 1:1
swap across the runtime reference prompts, the graphify hook's commit-detection
gate, and two bin/lib comment/message references.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

* chore(#191): remove vestigial gsd-sdk shim code from installer + projection

The gsd-sdk shim was already not wired up (no gsd-sdk bin in package.json;
buildWindowsShimTriple had zero call sites). Remove the dead code:
- shell-command-projection.cjs: buildWindowsShimTriple + formatSdkPathDiagnostic
  (+ their now-unused PACKAGE_NAME import) and exports
- install.js: the re-export wrappers + imports, the #3406 stale-standalone-sdk
  detection (detectStaleStandaloneSdk/formatStaleStandaloneSdkWarning + its
  global-install call site), and the exports

Preserved (retained, not gsd-sdk): buildCodexHookWindowsShimIR (#3426) — only
its comments referenced the gsd-sdk pattern; reworded. Also kept the
homePathCoveredByRc 'reopen your shell' branch in maybeSuggestPathExport — its
logic is bin-dir-agnostic, only the message mentioned gsd-sdk; reworded to use
the actual bin dir.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

* test(#191): update tests for retired gsd-sdk shim

- bug-3441/bug-3442: drop the formatSdkPathDiagnostic / buildWindowsShimTriple
  assertions (functions removed); retained PATH-action + drift-guard tests stay
- bug-505: remove the 'still exported' assertions for detectStaleStandaloneSdk /
  formatStaleStandaloneSdkWarning / the shim contract surface (#505 kept them;
  #191 removes them)
- graphify-auto-update: migrate the hook-dispatch inputs gsd-sdk query commit ->
  gsd-tools query commit to match the migrated commit hook

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

* docs(#191): point active docs at gsd-tools query (gsd-sdk shim retired)

Update the user/agent-facing docs (AGENTS, COMMANDS, CONFIGURATION, USER-GUIDE,
ship-pr-body-sections) that presented gsd-sdk query as a current command to
gsd-tools query. Historical docs (ADRs, PRDs, release notes) left untouched.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

* docs(#191): correct state.load vs state.json description for gsd-tools query

Adversarial-review (codex) finding: the migrated USER-GUIDE line claimed both
'gsd-tools query state.json' and 'state.load' resolve to the frontmatter-rebuild
handler. Verified they don't — state.load returns the CJS load shape
(config + state_raw + flags), state.json returns the frontmatter shape. Both are
available via gsd-tools query; corrected the text to say so.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

* chore(#191): add changeset for gsd-sdk shim retirement

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>

tests/graphify-auto-update.test.cjs

@@ -571,11 +571,11 @@ describe('auto-update', () => {
       'git pull --ff-only',
       'git rebase --continue',
       'git cherry-pick abc123',
-      // #3653 — `gsd-sdk query commit` invokes git via spawnSync('git', [...]),
+      // #3653 — `gsd-tools query commit` invokes git via spawnSync('git', [...]),
       // so the substring "git commit" never appears in tool_input.command.
       // The hook must match the user-facing SDK invocation directly.
-      'gsd-sdk query commit "docs: probe" --files .planning/STATE.md',
-      'npx gsd-sdk query commit "docs: probe" --files .planning/STATE.md',
+      'gsd-tools query commit "docs: probe" --files .planning/STATE.md',
+      'npx gsd-tools query commit "docs: probe" --files .planning/STATE.md',
     ]) {
       test(`dispatches on: ${cmd}`, (t) => {
         const tmpDir = createTempGitRepo({
@@ -610,7 +610,7 @@ describe('auto-update', () => {
         {
           tool_name: 'Bash',
           tool_input: {
-            command: 'gsd-sdk query commit-to-subrepo "msg" --files packages/foo',
+            command: 'gsd-tools query commit-to-subrepo "msg" --files packages/foo',
           },
         },
         { pathPrepend: mockBin },
@@ -623,13 +623,13 @@ describe('auto-update', () => {
     });
 
     // #3653 — only the SDK `commit` verb invokes git internally. Other
-    // `gsd-sdk query` verbs (phase.complete, roadmap.update-plan-progress,
+    // `gsd-tools query` verbs (phase.complete, roadmap.update-plan-progress,
     // state.begin-phase) mutate .md files but do NOT advance HEAD; matching
     // them would cause a spurious rebuild per state mutation.
     for (const cmd of [
-      'gsd-sdk query phase.complete 109',
-      'gsd-sdk query roadmap.update-plan-progress 109 W001',
-      'gsd-sdk query state.begin-phase 110',
+      'gsd-tools query phase.complete 109',
+      'gsd-tools query roadmap.update-plan-progress 109 W001',
+      'gsd-tools query state.begin-phase 110',
     ]) {
       test(`does NOT dispatch on non-HEAD-advancing SDK verb: ${cmd}`, (t) => {
         const tmpDir = createTempGitRepo({