§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test could previously reach the real api.moonshot.cn), and the outdated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-secrets/Cargo.toml

@@ -3,7 +3,7 @@ license = "Apache-2.0"
 edition.workspace = true
 name = "kigi-secrets"
 version.workspace = true
-description = "Regex sanitizer for Grok Build outbound data (Sentry / Mixpanel / product-event scrubbing)"
+description = "Regex sanitizer for Kigi outbound data (Sentry / Mixpanel / product-event scrubbing)"
 
 [dependencies]
 regex = { workspace = true }

crates/codegen/kigi-secrets/src/sanitizer.rs

@@ -336,7 +336,7 @@ mod tests {
             redact_secrets("just a normal log line"),
             Cow::Borrowed(_)
         ));
-        assert!(matches!(redact_secrets("model=grok-3"), Cow::Borrowed(_)));
+        assert!(matches!(redact_secrets("model=kigi-3"), Cow::Borrowed(_)));
     }
 
     /// Joins fixture fragments at runtime so realistic-looking fake tokens
@@ -461,14 +461,14 @@ mod tests {
 
     #[test]
     fn redacts_sensitive_url_query_params() {
-        let out = redact_secrets("callback https://x.ai/cb?code=ABC123XYZ&state=xyz789 failed");
+        let out = redact_secrets("callback https://kimi.com/cb?code=ABC123XYZ&state=xyz789 failed");
         assert!(!out.contains("ABC123XYZ"), "OAuth code leaked: {out}");
         assert!(!out.contains("xyz789"), "state leaked: {out}");
     }
 
     #[test]
     fn url_regex_excludes_trailing_punctuation() {
-        let out = redact_secrets("see `https://x.ai/cb?code=ABCD12345`");
+        let out = redact_secrets("see `https://kimi.com/cb?code=ABCD12345`");
         assert!(out.ends_with('`'), "trailing backtick lost: {out}");
     }