§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test could previously reach the real api.moonshot.cn), and the outdated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-workspace/src/permission/state.rs

@@ -16,11 +16,11 @@ pub struct PermissionState {
     /// Domains the user has approved for `web_fetch`
     /// during this session.
     pub allowed_web_fetch_domains: HashSet<String>,
-    /// Exact MCP tool names (e.g. `"grok_com_notion__notion-fetch"`)
+    /// Exact MCP tool names (e.g. `"kigi_com_notion__notion-fetch"`)
     /// the user has granted "always allow" for. Lookup is exact.
     pub allowed_mcp_tools: HashSet<String>,
     /// MCP server prefixes (everything before the first `__`,
-    /// e.g. `"grok_com_notion"`) for which the user has granted
+    /// e.g. `"kigi_com_notion"`) for which the user has granted
     /// "always allow" to every tool. Lookup is "tool name starts with
     /// `<prefix>__`".
     pub allowed_mcp_servers: HashSet<String>,
@@ -299,7 +299,7 @@ mod tests {
         let mut state = PermissionState::default();
         state
             .allowed_mcp_tools
-            .insert("grok_com_notion__notion-fetch".to_string());
+            .insert("kigi_com_notion__notion-fetch".to_string());
         state
             .allowed_mcp_tools
             .insert("linear__list_issues".to_string());
@@ -311,7 +311,7 @@ mod tests {
         assert!(
             restored
                 .allowed_mcp_tools
-                .contains("grok_com_notion__notion-fetch")
+                .contains("kigi_com_notion__notion-fetch")
         );
         assert!(restored.allowed_mcp_tools.contains("linear__list_issues"));
         assert!(restored.allowed_mcp_servers.is_empty());
@@ -322,14 +322,14 @@ mod tests {
         let mut state = PermissionState::default();
         state
             .allowed_mcp_servers
-            .insert("grok_com_slack".to_string());
+            .insert("kigi_com_slack".to_string());
         state.allowed_mcp_servers.insert("linear".to_string());
 
         let toml_str = toml::to_string_pretty(&state).unwrap();
         let restored: PermissionState = toml::from_str(&toml_str).unwrap();
 
         assert_eq!(restored.allowed_mcp_servers.len(), 2);
-        assert!(restored.allowed_mcp_servers.contains("grok_com_slack"));
+        assert!(restored.allowed_mcp_servers.contains("kigi_com_slack"));
         assert!(restored.allowed_mcp_servers.contains("linear"));
         assert!(restored.allowed_mcp_tools.is_empty());
     }