§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test could previously reach the real api.moonshot.cn), and the outdated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-pager-render/src/syntax.rs

@@ -1,8 +1,8 @@
 //! Syntax highlighting initialization.
 //!
 //! Provides lazily-initialized `Syntect` instances for code highlighting.
-//! Dark themes (GrokNight, TokyoNight) share `grok-night.tmTheme`;
-//! GrokDay uses `grok-day.tmTheme` with deepened colors for light backgrounds.
+//! Dark themes (KigiNight, TokyoNight) share `kigi-night.tmTheme`;
+//! KigiDay uses `kigi-day.tmTheme` with deepened colors for light backgrounds.
 
 use std::sync::OnceLock;
 
@@ -10,9 +10,9 @@ pub use kigi_markdown::Syntect;
 
 use crate::theme::ThemeKind;
 
-static SYNTECT_GROKNIGHT: OnceLock<Syntect> = OnceLock::new();
+static SYNTECT_KIGINIGHT: OnceLock<Syntect> = OnceLock::new();
 static SYNTECT_TOKYONIGHT: OnceLock<Syntect> = OnceLock::new();
-static SYNTECT_GROKDAY: OnceLock<Syntect> = OnceLock::new();
+static SYNTECT_KIGIDAY: OnceLock<Syntect> = OnceLock::new();
 
 /// Convert syntect style to ratatui foreground-only style, quantized for terminal color support.
 pub fn syntect_to_ratatui_fg(style: syntect::highlighting::Style) -> ratatui::style::Style {
@@ -66,14 +66,14 @@ pub fn highlight_line(
 /// Returns the syntect instance matching the active theme.
 pub fn get_syntect() -> &'static Syntect {
     match crate::theme::Theme::current_kind() {
-        ThemeKind::GrokNight
+        ThemeKind::KigiNight
         | ThemeKind::RosePineMoon
         | ThemeKind::OscuraMidnight
-        | ThemeKind::Auto => SYNTECT_GROKNIGHT
-            .get_or_init(|| Syntect::new(include_bytes!("../assets/grok-night.tmTheme"))),
+        | ThemeKind::Auto => SYNTECT_KIGINIGHT
+            .get_or_init(|| Syntect::new(include_bytes!("../assets/kigi-night.tmTheme"))),
         ThemeKind::TokyoNight => SYNTECT_TOKYONIGHT
             .get_or_init(|| Syntect::new(include_bytes!("../assets/tokyo-night.tmTheme"))),
-        ThemeKind::GrokDay => SYNTECT_GROKDAY
-            .get_or_init(|| Syntect::new(include_bytes!("../assets/grok-day.tmTheme"))),
+        ThemeKind::KigiDay => SYNTECT_KIGIDAY
+            .get_or_init(|| Syntect::new(include_bytes!("../assets/kigi-day.tmTheme"))),
     }
 }