§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test could previously reach the real api.moonshot.cn), and the outdated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-hooks/src/trust.rs

@@ -6,7 +6,7 @@ use std::path::{Path, PathBuf};
 // exist only to migrate prior grants out of the legacy file.
 
 /// Path to the legacy project-hook trust file
-/// (`<user_kigi_home>/trusted-hook-projects`), or `None` when no user grok home
+/// (`<user_kigi_home>/trusted-hook-projects`), or `None` when no user kigi home
 /// resolves. Retained only for the one-time migration into folder-trust.
 pub fn legacy_trust_file_path() -> Option<PathBuf> {
     Some(kigi_config::user_kigi_home()?.join("trusted-hook-projects"))
@@ -59,7 +59,7 @@ fn is_hook_disabled_with_file(hook_name: &str, file: &Path) -> bool {
 /// Disable a hook by name. Adds to .
 pub fn disable_hook(hook_name: &str) -> Result<(), String> {
     let file = disabled_hooks_file_path()
-        .ok_or_else(|| "no user grok home (set $KIGI_SHARE_DIR or $HOME)".to_string())?;
+        .ok_or_else(|| "no user kigi home (set $KIGI_SHARE_DIR or $HOME)".to_string())?;
     disable_hook_with_file(hook_name, &file)
 }
 
@@ -122,7 +122,7 @@ fn enable_hook_with_file(hook_name: &str, file: &Path) -> Result<bool, String> {
     Ok(true)
 }
 
-/// Returns the path to `$KIGI_SHARE_DIR/disabled-hooks`, or `None` when no user grok
+/// Returns the path to `$KIGI_SHARE_DIR/disabled-hooks`, or `None` when no user kigi
 /// home resolves.
 fn disabled_hooks_file_path() -> Option<PathBuf> {
     Some(kigi_config::user_kigi_home()?.join("disabled-hooks"))
@@ -134,9 +134,9 @@ mod tests {
 
     /// Each test creates its own legacy file in its own temp dir -- no shared state.
     fn trust_file_in(dir: &Path) -> PathBuf {
-        let grok_dir = dir.join(".kigi");
-        std::fs::create_dir_all(&grok_dir).unwrap();
-        grok_dir.join("trusted-hook-projects")
+        let kigi_dir = dir.join(".kigi");
+        std::fs::create_dir_all(&kigi_dir).unwrap();
+        kigi_dir.join("trusted-hook-projects")
     }
 
     #[test]