§9 acceptance: grep-zero sweep — every internal x.ai/grok identifier renamed

The PRD's first acceptance gate now holds: grep -RinE '\bx\.ai\b|grok'
crates/ --include='*.rs' → 0 matches (exempt: NOTICE and third-party
license archives, README provenance, and the required 'Based on Grok
Build Open Source' attribution, now sourced from version_attribution.txt).

Wire-visible renames (both sides in this repo, changed in lockstep):
- Auth method id 'grok.com' → 'kimi-code' (AuthMethodKind::KimiCode).
- Every x.ai/* and _x.ai/* ACP ext method and meta key → kigi/* /
  _kigi/* (~200 names; grokShell → kigiShell). Session-file replay keeps
  a read-side alias for the legacy '_x.ai/session/update' method so
  existing updates.jsonl histories load; writes emit only the new name
  (both directions test-pinned).
- Agent types grok-build* → kigi* with a documented legacy-prefix alias
  at resolution time so persisted sessions keep resolving.
- ToolNamespace/BuiltinAgentName GrokBuild* → Kigi* (wire snake_case
  kigi/kigi_concise/kigi_hashline; schema regenerated); grok_build
  implementation dirs renamed to kigi*.
- x-grok-* headers → x-kigi-*, __GROK_* sentinels → __KIGI_*, themes
  grokday/groknight → kigiday/kiginight (old persisted values fall back
  to the default theme), web_fetch allowlist xAI hosts → kimi.com +
  moonshot platforms, changelog CDN → this repo, grok-build changelog
  archives deleted.
- BYOK default endpoint removed: [endpoints] api_base_url is now truly
  optional with NO default — consumers fail fast with the flag name when
  unset (no silent x.ai egress). Mock harnesses inject it explicitly.
- System-prompt identity fixed: 'released by xAI' → 'an unofficial
  community CLI for Kimi' (template + regenerated encrypted form).

Also repaired pre-existing grok-era test debt found by the sweep: the
stale trace_classify default-model pin, the grok-pager UA label test,
pty-harness stale-binary reuse and non-hermetic moonshot routing (a PTY
test could previously reach the real api.moonshot.cn), and the outdated
oauth fixture scope key.

Gates: §9 grep 0; fmt clean; workspace check/clippy 0/0 (-D warnings);
FULL cargo test --workspace: 234 suites, 21,961 passed, 0 failed;
deny advisories ok.

crates/codegen/kigi-memory/src/index.rs

@@ -472,7 +472,7 @@ impl MemoryIndex {
     ///
     /// An empty string means no claim is active.  A non-empty claim means
     /// a session currently owns the reindex lock (or a crashed session left
-    /// a stale one).  Used by `grok memory doctor` to detect stuck states.
+    /// a stale one).  Used by `kigi memory doctor` to detect stuck states.
     pub fn get_reindex_claim(&self) -> String {
         self.db
             .query_row(
@@ -485,7 +485,7 @@ impl MemoryIndex {
 
     /// Return all distinct file paths that have at least one indexed chunk.
     ///
-    /// Used by `grok memory doctor` to detect orphaned chunks (chunks whose
+    /// Used by `kigi memory doctor` to detect orphaned chunks (chunks whose
     /// source file has since been deleted).
     pub fn all_indexed_paths(&self) -> Result<Vec<String>, rusqlite::Error> {
         let mut stmt = self
@@ -1179,13 +1179,13 @@ mod tests {
     ///
     /// 1. Index a file.
     /// 2. Delete the file from disk (simulates a user removing a session log).
-    /// 3. Run the same orphan-removal logic as `grok memory reindex`:
+    /// 3. Run the same orphan-removal logic as `kigi memory reindex`:
     ///    compare `all_indexed_paths()` against current files and call
     ///    `delete_path()` for paths that no longer exist.
     /// 4. Verify the stale chunks are gone and are no longer searchable.
     ///
-    /// This proves that `grok memory reindex`'s Phase 1 actually fixes the
-    /// state that `grok memory doctor` warns about.
+    /// This proves that `kigi memory reindex`'s Phase 1 actually fixes the
+    /// state that `kigi memory doctor` warns about.
     #[test]
     fn test_reindex_maintenance_removes_orphaned_chunks() {
         let tmp = TempDir::new().unwrap();
@@ -1206,7 +1206,7 @@ mod tests {
         // Delete the file — now it is orphaned in the index.
         std::fs::remove_file(&file).unwrap();
 
-        // Simulate `grok memory reindex` Phase 1: compare indexed vs current.
+        // Simulate `kigi memory reindex` Phase 1: compare indexed vs current.
         let current: std::collections::BTreeSet<String> = vec![].into_iter().collect(); // empty = no files
         let indexed = idx.all_indexed_paths().unwrap();
         for path in &indexed {
@@ -1225,7 +1225,7 @@ mod tests {
 
     /// A fresh (non-stale) reindex claim blocks `try_claim_reindex`.
     ///
-    /// Verifies that `grok memory reindex` Phase 0 correctly bails when a
+    /// Verifies that `kigi memory reindex` Phase 0 correctly bails when a
     /// live session holds a fresh claim — i.e., the CLI cannot steal a live
     /// session's lock and then mutate the index concurrently.
     #[test]
@@ -1256,10 +1256,10 @@ mod tests {
         idx.release_claim();
     }
 
-    /// `grok memory reindex` Phase 3 resets the stale reindex claim.
+    /// `kigi memory reindex` Phase 3 resets the stale reindex claim.
     ///
     /// Verifies that `release_claim()` clears `meta.reindex_claim` so that
-    /// `grok memory doctor` no longer reports a stale lock after reindex runs.
+    /// `kigi memory doctor` no longer reports a stale lock after reindex runs.
     #[test]
     fn test_reindex_maintenance_resets_stale_claim() {
         let tmp = TempDir::new().unwrap();
@@ -1274,7 +1274,7 @@ mod tests {
             "claim must be set before Phase 3"
         );
 
-        // Simulate `grok memory reindex` Phase 3: release the claim.
+        // Simulate `kigi memory reindex` Phase 3: release the claim.
         idx.release_claim();
 
         assert_eq!(