§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test could previously reach the real api.moonshot.cn), and the outdated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-shell/src/session/goal_tracker.rs

@@ -252,7 +252,7 @@ impl GoalHistoryEntry {
 // GoalOrchestration (full persisted state)
 
 /// Generate a short opaque identifier used to scope the per-goal
-/// scratch root (`<temp_dir>/grok-goal-<id>`) and the verifier
+/// scratch root (`<temp_dir>/kigi-goal-<id>`) and the verifier
 /// verdict/details files inside it.
 ///
 /// The id is a 12-char prefix of a UUIDv4 simple form — ~48 bits of
@@ -267,13 +267,13 @@ pub(crate) fn generate_verifier_id() -> String {
     s
 }
 
-/// Private per-goal scratch root: `<temp_dir>/grok-goal-<verifier_id>`.
+/// Private per-goal scratch root: `<temp_dir>/kigi-goal-<verifier_id>`.
 ///
 /// Rooted at [`std::env::temp_dir`] (respects `TMPDIR`) and namespaced by the
 /// goal's `verifier_id`, so concurrent goals never collide and cleanup of one
 /// never touches another. Removed wholesale on every terminal goal transition.
 pub(crate) fn goal_scratch_root(verifier_id: &str) -> PathBuf {
-    std::env::temp_dir().join(format!("grok-goal-{verifier_id}"))
+    std::env::temp_dir().join(format!("kigi-goal-{verifier_id}"))
 }
 
 /// Create (or verify) the goal's scratch root, locked to the owner
@@ -1646,7 +1646,7 @@ mod tests {
     /// fresh values on every call. The fixed length is part of the
     /// public contract — verifier file paths embed it verbatim, and
     /// drift here would silently invalidate the documented
-    /// `grok-goal-<12 hex chars>` scratch-root format (and the
+    /// `kigi-goal-<12 hex chars>` scratch-root format (and the
     /// 12-hex restore validation in `from_snapshot`).
     #[test]
     fn generate_verifier_id_is_short_hex_and_unique() {
@@ -2539,7 +2539,7 @@ mod tests {
         activate_tracker(&mut t);
         t.update_live_progress(
             100,
-            vec![("grok-4".to_owned(), 60), ("grok-3".to_owned(), 40)],
+            vec![("kigi-4".to_owned(), 60), ("kigi-3".to_owned(), 40)],
             200_000,
             50,
             3,
@@ -3081,11 +3081,11 @@ mod tests {
         let mut o = make_base_orchestration();
         o.skeptic_model_assignment = vec![
             crate::util::config::GoalRoleModel {
-                model: "grok-4".to_string(),
+                model: "kigi-4".to_string(),
                 agent_type: "general-purpose".to_string(),
             },
             crate::util::config::GoalRoleModel {
-                model: "grok-4.5".to_string(),
+                model: "kigi-4.5".to_string(),
                 agent_type: "cursor".to_string(),
             },
         ];
@@ -3132,7 +3132,7 @@ mod tests {
             activate_tracker(&mut t);
             t.snapshot_mut().unwrap().skeptic_model_assignment =
                 vec![crate::util::config::GoalRoleModel {
-                    model: "grok-4".to_string(),
+                    model: "kigi-4".to_string(),
                     agent_type: "general-purpose".to_string(),
                 }];
             let applied = match ending {
@@ -3170,22 +3170,22 @@ mod tests {
     }
 
     /// The scratch path helpers derive the pinned layout from
-    /// `temp_dir()` + `verifier_id`: a `grok-goal-<vid>` root with an
+    /// `temp_dir()` + `verifier_id`: a `kigi-goal-<vid>` root with an
     /// `implementer/` subdir and per-index `skeptic-<idx>/` subdirs.
     #[test]
     fn scratch_path_helpers_derive_pinned_layout() {
         let root = goal_scratch_root("vid123");
-        assert_eq!(root, std::env::temp_dir().join("grok-goal-vid123"));
+        assert_eq!(root, std::env::temp_dir().join("kigi-goal-vid123"));
         assert_eq!(
             implementer_scratch_dir("vid123"),
             std::env::temp_dir()
-                .join("grok-goal-vid123")
+                .join("kigi-goal-vid123")
                 .join("implementer"),
         );
         assert_eq!(
             skeptic_scratch_dir("vid123", 2),
             std::env::temp_dir()
-                .join("grok-goal-vid123")
+                .join("kigi-goal-vid123")
                 .join("skeptic-2"),
         );
     }