§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test could previously reach the real api.moonshot.cn), and the outdated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-compaction/src/intra_compaction/config.rs

@@ -4,7 +4,7 @@ use serde::{Deserialize, Serialize};
 
 /// Which targets intra-compaction may compact.
 ///
-/// - `FullReplace` (default): grok-build's full-replace strategy — summarize
+/// - `FullReplace` (default): kigi's full-replace strategy — summarize
 ///   the *whole* conversation (prior history + accumulated steps) and rebuild
 ///   context from scratch as `[system] + [summary]`. Drives the shared
 ///   `code_compaction` summarizer directly; no tail is kept.
@@ -56,7 +56,7 @@ pub enum IntraSummarizer {
 ///
 /// When `enabled = false` (default), no intra-compaction runs for that agent.
 ///
-/// Uses **percentage** thresholds (borrowed from grok-shell's
+/// Uses **percentage** thresholds (borrowed from kigi-shell's
 /// `CompactionPolicy`) for portability across models with different context
 /// windows.
 ///
@@ -65,7 +65,7 @@ pub enum IntraSummarizer {
 /// LLM call, audit) and a **mode-specific** block whose fields are each read by
 /// only a subset of modes (see the per-field `[...]` tags). In particular,
 /// `FullReplace` — the default — ignores `min_steps_before_compact` at trigger
-/// time (token threshold only, matching grok-build) and also ignores
+/// time (token threshold only, matching kigi) and also ignores
 /// `summarizer`, `target_threshold_percent`, `steps_trigger_ratio`, and
 /// `user_message_truncate_chars`. The field remains on this config for all
 /// modes (YAML / remote agent config / defaults); only enforcement is mode-dependent.
@@ -107,7 +107,7 @@ pub struct IntraCompactionConfig {
     /// **Enforcement:** applied for `StepsOnly` / `HistoryOnly` /
     /// `HistoryThenSteps`. **Ignored** when [`mode`](Self::mode) is
     /// [`IntraCompactionMode::FullReplace`] (token threshold alone, same idea
-    /// as grok-build full-replace auto-compact). Worthless early passes are
+    /// as kigi full-replace auto-compact). Worthless early passes are
     /// still limited by [`min_compactable_tokens`](Self::min_compactable_tokens)
     /// / reduction guards after a trigger.
     pub min_steps_before_compact: u32,
@@ -192,7 +192,7 @@ pub struct IntraCompactionConfig {
     //    preamble). --
     /// [HistoryOnly / HistoryThenSteps] Character threshold above which an
     /// original user message gets middle-truncated when included in the
-    /// `<grok_user_queries>` preamble prepended to the history compaction
+    /// `<kigi_user_queries>` preamble prepended to the history compaction
     /// summary. Mirrors the inter-compaction Basic threshold. Has no
     /// effect for `Steps` target — steps compaction has no user-queries
     /// preamble. Default: `3000`. (Not always exposed by remote agent-config