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test could previously reach the real api.moonshot.cn), and the outdated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

@@ -488,7 +488,7 @@ mod tests {
     #[test]
     fn origin_client_info_from_meta_extracts_identifier_and_version() {
         let meta = serde_json::json!({
-            "clientIdentifier": "grok-desktop",
+            "clientIdentifier": "kigi-desktop",
             "clientVersion": "1.2.3",
         })
         .as_object()
@@ -497,7 +497,7 @@ mod tests {
         assert_eq!(
             origin_client_info_from_meta(Some(&meta)),
             Some(OriginClientInfo {
-                product: "grok-desktop".to_string(),
+                product: "kigi-desktop".to_string(),
                 version: Some("1.2.3".to_string()),
             })
         );
@@ -505,8 +505,11 @@ mod tests {
 
     #[test]
     fn origin_client_info_from_meta_uses_client_type_when_identifier_absent() {
+        // `kigi_web` is used (not the pager) because its user-agent label is
+        // distinct from the Generic default's `kigi` — a clientType parse
+        // failure would fall back to Generic and this assert would catch it.
         let meta = serde_json::json!({
-            "clientType": "grok_pager",
+            "clientType": "kigi_web",
             "clientVersion": "0.1.2",
         })
         .as_object()
@@ -515,28 +518,39 @@ mod tests {
         assert_eq!(
             origin_client_info_from_meta(Some(&meta)),
             Some(OriginClientInfo {
-                product: "grok-pager".to_string(),
+                product: "kigi-web".to_string(),
                 version: Some("0.1.2".to_string()),
             })
         );
+        // First-party clients collapse to the plain `kigi` product (PRD F3).
+        let pager_meta = serde_json::json!({ "clientType": "kigi_pager" })
+            .as_object()
+            .cloned()
+            .unwrap();
+        assert_eq!(
+            origin_client_info_from_meta(Some(&pager_meta))
+                .expect("pager clientType resolves")
+                .product,
+            "kigi"
+        );
     }
 
     #[test]
     fn merge_origin_client_info_preserves_primary_product_and_backfills_version() {
         let merged = merge_origin_client_info(
             Some(OriginClientInfo {
-                product: "grok-web".to_string(),
+                product: "kigi-web".to_string(),
                 version: None,
             }),
             Some(OriginClientInfo {
-                product: "grok-desktop".to_string(),
+                product: "kigi-desktop".to_string(),
                 version: Some("1.2.3".to_string()),
             }),
         );
         assert_eq!(
             merged,
             Some(OriginClientInfo {
-                product: "grok-web".to_string(),
+                product: "kigi-web".to_string(),
                 version: Some("1.2.3".to_string()),
             })
         );
@@ -545,18 +559,18 @@ mod tests {
     #[test]
     fn session_user_agent_string_renders_expected_variants() {
         let with_version = session_user_agent_string(&OriginClientInfo {
-            product: "grok-desktop".to_string(),
+            product: "kigi-desktop".to_string(),
             version: Some("1.2.3".to_string()),
         });
-        assert!(with_version.starts_with("grok-desktop/1.2.3 kigi/"));
+        assert!(with_version.starts_with("kigi-desktop/1.2.3 kigi/"));
         assert!(with_version.contains(" ("));
 
         let without_version = session_user_agent_string(&OriginClientInfo {
-            product: "grok-web".to_string(),
+            product: "kigi-web".to_string(),
             version: None,
         });
-        assert!(without_version.starts_with("grok-web kigi/"));
-        assert!(!without_version.starts_with("grok-web/"));
+        assert!(without_version.starts_with("kigi-web kigi/"));
+        assert!(!without_version.starts_with("kigi-web/"));
     }
 
     #[test]