§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test could previously reach the real api.moonshot.cn), and the outdated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/common/kigi-tool-runtime/src/notification.rs

@@ -266,7 +266,7 @@ pub struct MonitorEvent {
     pub raw_text: String,
 }
 
-/// Snapshot of a background task's state. Identical shape to the Grok
+/// Snapshot of a background task's state. Identical shape to the Kigi
 /// Build `TaskSnapshot` so subscribers can decode without per-source
 /// adapters.
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]

crates/common/kigi-tool-runtime/src/render.rs

@@ -199,7 +199,7 @@ pub fn extract_content_blocks(value: &Value) -> Vec<ContentBlock> {
     }
 
     if let Some(obj) = value.as_object() {
-        // grok-build `ToolRunResult`: the model sees `prompt_text` (reminders
+        // kigi `ToolRunResult`: the model sees `prompt_text` (reminders
         // appended), never a JSON dump of the structured result.
         if let Some(Value::String(prompt_text)) = obj.get("prompt_text")
             && obj.contains_key("output")

crates/common/kigi-tool-runtime/src/tool.rs

@@ -157,7 +157,7 @@ pub enum ToolProgress {
 /// across the wire boundary without re-encoding.
 ///
 /// The `Image` variant carries optional metadata fields (`media_id`,
-/// `filename`, `path`, `metadata`) that the Grok SLOP converter uses to
+/// `filename`, `path`, `metadata`) that the Kigi SLOP converter uses to
 /// build `Media` objects with the right identifiers and file paths. Tool
 /// authors populate these in their `ToolOutput::model_output()` impls so
 /// downstream consumers don't need to know the concrete tool type.
@@ -169,11 +169,11 @@ pub enum ContentBlock {
     Text { text: String },
     /// Image. `mime_type` is e.g. `"image/png"`; `data` is base64.
     ///
-    /// Optional metadata fields are used by the Grok SLOP converter to
+    /// Optional metadata fields are used by the Kigi SLOP converter to
     /// produce `Media` objects with the correct identifiers:
     /// - `media_id`: unique image ID for referencing in subsequent tool calls
     /// - `filename`: human-readable filename (e.g. `"xK29f.png"`)
-    /// - `path`: file path on the Grok Computer filesystem
+    /// - `path`: file path on the Kigi Computer filesystem
     /// - `metadata`: arbitrary key-value pairs (e.g. `title`, `webpage_url`)
     Image {
         #[serde(alias = "mimeType")]