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test could previously reach the real api.moonshot.cn), and the outdated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

@@ -1,7 +1,7 @@
 //! Centralized unified log for cross-component session observability.
 //!
 //! Shell writes directly via [`emit()`]. Pager and desktop forward entries
-//! over ACP (`x.ai/log` notifications); shell receives them in
+//! over ACP (`kigi/log` notifications); shell receives them in
 //! [`ingest_client_entries()`] and writes on their behalf.
 
 use std::fs::{self, File, OpenOptions};
@@ -29,7 +29,7 @@ const LOG_FILE: &str = "unified.jsonl";
 pub const MAX_SIZE: u64 = 5 * 1024 * 1024; // 5 MB
 
 /// ACP method name for unified log notifications.
-pub const LOG_METHOD: &str = "x.ai/log";
+pub const LOG_METHOD: &str = "kigi/log";
 
 // ---------------------------------------------------------------------------
 // Log entry types
@@ -52,12 +52,12 @@ pub enum LogSource {
     #[strum(serialize = "shell")]
     #[serde(rename = "shell")]
     Shell,
-    #[strum(serialize = "grok-pager")]
-    #[serde(rename = "grok-pager")]
-    GrokPager,
-    #[strum(serialize = "grok-desktop")]
-    #[serde(rename = "grok-desktop")]
-    GrokDesktop,
+    #[strum(serialize = "kigi-pager")]
+    #[serde(rename = "kigi-pager")]
+    KigiPager,
+    #[strum(serialize = "kigi-desktop")]
+    #[serde(rename = "kigi-desktop")]
+    KigiDesktop,
 }
 
 /// A single unified log entry, written as one JSONL line.
@@ -95,7 +95,7 @@ pub struct LogEntry {
     pub ctx: Option<serde_json::Value>,
 }
 
-/// Wire format for the `x.ai/log` ACP notification params.
+/// Wire format for the `kigi/log` ACP notification params.
 #[derive(Debug, Clone, Serialize, Deserialize)]
 pub struct LogNotificationParams {
     /// Source component identifier.
@@ -254,7 +254,7 @@ pub fn emit(lvl: LogLevel, msg: &str, sid: Option<&str>, ctx: Option<serde_json:
 
 /// Ingest a batch of log entries from a client (pager or desktop).
 ///
-/// Called by the `x.ai/log` notification handler. Entries from
+/// Called by the `kigi/log` notification handler. Entries from
 /// [`LogSource::Shell`] are rejected to prevent spoofing.
 pub fn ingest_client_entries(src: LogSource, entries: &[ClientLogEntry]) {
     if matches!(src, LogSource::Shell) || entries.is_empty() {
@@ -381,7 +381,7 @@ mod tests {
     fn log_entry_serializes_full() {
         let entry = LogEntry {
             ts: "2025-07-14T10:30:00.123Z".into(),
-            src: LogSource::GrokPager,
+            src: LogSource::KigiPager,
             pid: Some(4242),
             ver: Some("0.1.211".into()),
             lvl: LogLevel::Warn,
@@ -465,7 +465,7 @@ mod tests {
         for bad in &[
             r#"{"src":"evil","entries":[]}"#,
             r#"{"src":"","entries":[]}"#,
-            r#"{"src":"GROK-PAGER","entries":[]}"#,
+            r#"{"src":"KIGI-PAGER","entries":[]}"#,
         ] {
             assert!(serde_json::from_str::<LogNotificationParams>(bad).is_err());
         }
@@ -474,7 +474,7 @@ mod tests {
     #[test]
     fn notification_params_round_trip() {
         let params = LogNotificationParams {
-            src: LogSource::GrokPager,
+            src: LogSource::KigiPager,
             entries: vec![
                 ClientLogEntry {
                     ts: "2025-07-14T10:30:00.123Z".into(),