§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test could previously reach the real api.moonshot.cn), and the outdated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/render/osc8.rs

@@ -91,7 +91,7 @@ fn link_finder() -> &'static LinkFinder {
 }
 
 /// One path segment without spaces (`main.rs`, `.kigi`, `@scope`). Leading `.`
-/// matches dot-directories and `%` matches percent-encoded segments — grok
+/// matches dot-directories and `%` matches percent-encoded segments — kigi
 /// session media lives under `~/.kigi/sessions/%2F…/images/1.jpg`.
 const PATH_SEGMENT: &str = r"[a-zA-Z0-9_@.%][a-zA-Z0-9._+@%\-]*";
 
@@ -565,7 +565,7 @@ mod tests {
         std::fs::write(dir.path().join("images/1.jpg"), b"x").unwrap();
         let media = vec![dir.path().join("images/1.jpg")];
 
-        assert!(local_link_to_file_url("https://x.ai", &media).is_none());
+        assert!(local_link_to_file_url("https://kimi.com", &media).is_none());
         assert!(local_link_to_file_url("mailto:a@b.c", &media).is_none());
         assert!(local_link_to_file_url("#section", &media).is_none());
         // Relative path that isn't a known generated media file.
@@ -786,13 +786,14 @@ mod tests {
 
     #[test]
     fn scan_content_x_offset_applied() {
-        let line = make_line("https://x.ai");
+        let line = make_line("https://kimi.com");
         let mut overlay = LinkOverlay::new();
         scan_unjoined(std::iter::once((0, &line)), 10, &[], &mut overlay);
 
         assert_eq!(overlay.links().len(), 1);
         assert_eq!(overlay.links()[0].col_start, 10);
-        assert_eq!(overlay.links()[0].col_end, 10 + 12);
+        // 16 == "https://kimi.com".len()
+        assert_eq!(overlay.links()[0].col_end, 10 + 16);
     }
 
     // ── File path detection ──
@@ -856,7 +857,7 @@ mod tests {
     }
 
     #[test]
-    fn scan_detects_grok_session_media_path() {
+    fn scan_detects_kigi_session_media_path() {
         // Dot-directory (`.kigi`), percent-encoded session segment, and a
         // trailing sentence period — the shape of media-tool output prose.
         let line = make_line("Saved to /Users/alice/.kigi/sessions/%2Fabc/00000000/images/1.jpg.");
@@ -1097,12 +1098,12 @@ mod tests {
 
     #[test]
     fn scan_file_path_with_dots_and_hyphens() {
-        let line = make_line("Reading /tmp/grok-impl-summary.md now.");
+        let line = make_line("Reading /tmp/kigi-impl-summary.md now.");
         let mut overlay = LinkOverlay::new();
         scan_unjoined(std::iter::once((0, &line)), 0, &[], &mut overlay);
 
         assert_eq!(overlay.links().len(), 1);
-        assert_eq!(&*overlay.links()[0].url, "file:///tmp/grok-impl-summary.md");
+        assert_eq!(&*overlay.links()[0].url, "file:///tmp/kigi-impl-summary.md");
     }
 
     #[test]
@@ -1188,7 +1189,7 @@ mod tests {
     #[test]
     fn scan_detects_tilde_file_path() {
         // The user's example: a `~/Desktop/…md` path in agent output.
-        let raw = "~/Desktop/grok-pager-retention-findings-2026-06-06.md";
+        let raw = "~/Desktop/kigi-pager-retention-findings-2026-06-06.md";
         // Skip when no home directory is resolvable (e.g. minimal sandbox):
         // the tilde stays unexpanded and cannot form an absolute file URL.
         let Ok(expected) = url::Url::from_file_path(shellexpand::tilde(raw).as_ref()) else {