M0: compilable skeleton — Kigi 0.1.0 fork surgery

Hard fork of xai-org/grok-build (Apache-2.0) re-targeted as Kigi, an
unofficial Kimi Code CLI community build.

Rename & identity
- 72 xai-*/xai-grok-* crates -> kigi-* (explicit: xai-grok-pager-bin ->
  kigi-bin [binary `kigi`], xai-grok-pager -> kigi-tui; rest mechanical);
  ptyctl, ptyctl-cli, third_party/ unchanged; proto package
  xai.grok.tools.v1 -> kigi.tools.v1
- Config home ~/.kigi (KIGI_SHARE_DIR override), env prefix GROK_* ->
  KIGI_*, `kigi --version` carries the unofficial-community-build notice
- clap identity, help text, startup banner, prompt templates rebranded
  (templates re-encrypted)

Deletions (PRD removal list #5/#6/#7/#9/#10)
- voice input (xai-grok-voice) and all TUI wiring
- telemetry: Mixpanel client, external OTel stream, Sentry, OTLP layers,
  trace/GCS/S3 upload queues (kigi-file-utils halved), workspace upload
  module & dc_log, heap-profile uploader, auth-diagnostics uploader,
  session-analytics halves of feedback; local zero-egress observability
  preserved in new kigi-log crate (unified log, --debug firehose,
  subsystem file logs, opt-in instrumentation)
- announcements (crate, remote-settings fields, TUI surfaces)
- plugin marketplace (crate, sources/browse/CTA/extensions-modal tab);
  direct plugin install/uninstall/update via kigi-agent git_install kept
- relay/gateway/assets endpoints and features (agent relay, headless
  relay transport, gateway bridge, LeaderEnvUrls); leader IPC socket now
  ~/.kigi/leader.sock + KIGI_LEADER_SOCKET, no ws-url derivation
- functional types rehomed instead of deleted: PermissionMode ->
  kigi-config-types, McpInitStrategy -> kigi-mcp, PrCreationSource ->
  session signals, TerminalDiagnostics -> kigi-pager-render, agent_id ->
  shell util

Endpoints
- kigi-env rewritten: single production KigiEndpoints {coding_api_base_url
  https://api.kimi.com/coding/v1 (KIGI_CODE_BASE_URL), oauth_host
  https://auth.kimi.com (KIGI_OAUTH_HOST), update_base_url (GitHub
  Releases API), upgrade_page_url}; GrokBuildEnvironment enum deleted

Toolchain & workspace hygiene
- Rust 1.97.0 pinned; edition 2024; full cargo update; git2 hoisted to
  workspace at 0.21 (Option->Result API migration), quick-xml 0.41
- Root Cargo.toml hand-maintained (PRD §8.1): version 0.1.0 inherited by
  all members, members sorted, unused deps pruned
- cargo-deny advisories gate (deny.toml with documented transitive
  exceptions); CI workflow (check/clippy/fmt/deny/test, macOS+Linux)
- cross-crate test seams re-gated behind `test-support` cargo feature;
  insta snapshot baselines renamed to the kigi_tui prefix
- clippy --workspace --all-targets: zero warnings; fmt clean

Fixes surfaced by the port
- updater probe/installer divergence (bin/kigi vs bin/grok symlink set)
- idle model-metadata refresh dead under KIGI_CODE_BASE_URL override
  (new is_effective_coding_endpoint_url, loopback+override aware)
- macOS symlinked-TMPDIR fixture canonicalization (foreign_sessions,
  fast-worktree); RSS measurement tests serialized via serial_test

Docs & legal (Apache §4)
- NOTICE added (upstream attribution + change statement); THIRD-PARTY
  notices sustained; kigi-tools ported-code notices extended; README,
  CONTRIBUTING, SECURITY, AGENTS.md rewritten

Out of scope for M0 (tracked): Kimi auth/inference (M1), search/fetch,
command parity, config import (M2), Computer Hub excision & final
brand-token sweep (M2), distribution & self-update rewrite (M3).

crates/common/kigi-compaction/src/code_compaction/observer.rs

@@ -0,0 +1,73 @@
+//! Observability seam for the full-replace (grok-build) pass.
+//!
+//! The shared orchestrator reports per-attempt and terminal outcomes through
+//! this trait so each harness can emit its own telemetry (grok-build:
+//! `CompactionAttempt` rows, `CompactionRetryDegraded` events, span records,
+//! request-artifact persistence) without the shared crate depending on a
+//! telemetry backend. Mirrors
+//! [`IntraCompactionObserver`](crate::intra_compaction::IntraCompactionObserver)
+//! / [`InterCompactionObserver`](crate::inter_compaction::InterCompactionObserver).
+//!
+//! Emission points are part of the behavior contract: the grok-build observer
+//! preserves the pre-migration `CompactionAttempt`/`CompactionRetryDegraded`
+//! semantics byte-for-byte.
+
+use std::time::Duration;
+
+/// Classified outcome of a single full-replace sample attempt.
+///
+/// The harness turns this into its per-attempt telemetry row. `summary` is the
+/// raw model output (the harness bounds/captures it as needed); it is borrowed
+/// for the duration of the callback so no allocation happens on the hot path.
+#[derive(Debug)]
+pub enum FullReplaceAttemptOutcome<'a> {
+    /// A usable, non-degenerate summary was produced; the pass will succeed.
+    Success {
+        /// Raw model summary text.
+        summary: &'a str,
+    },
+    /// The model returned an empty / whitespace-only response.
+    EmptyResponse {
+        /// Whether the orchestrator will retry after this attempt.
+        will_retry: bool,
+    },
+    /// The cleaned summary seed was too short to carry the conversation's task
+    /// state; retried like a transient failure.
+    Degenerate {
+        /// Raw model summary text (still captured for offline inspection).
+        summary: &'a str,
+        /// Whether the orchestrator will retry after this attempt.
+        will_retry: bool,
+    },
+    /// The sampler returned an error.
+    Failure {
+        /// Rendered error message.
+        message: &'a str,
+        /// Whether re-sending the *same* input cannot help (auth / schema /
+        /// size). Transient failures (timeout / stream blip / 5xx) are `false`.
+        deterministic: bool,
+        /// Whether the failure was a context-length overflow — the signal the
+        /// harness uses to step its input ladder rather than suppress.
+        context_overflow: bool,
+        /// Whether the orchestrator will retry after this attempt (always
+        /// `false` for deterministic failures and context overflows).
+        will_retry: bool,
+    },
+}
+
+/// Receives full-replace compaction outcomes. All methods default to no-ops so
+/// harnesses without telemetry (and tests) can use `()`.
+pub trait FullReplaceObserver: Send + Sync {
+    /// One sample attempt finished with the given classified outcome.
+    /// `attempt` is 1-based and cumulative across the pass.
+    fn on_attempt(&self, _attempt: u32, _outcome: &FullReplaceAttemptOutcome<'_>) {}
+
+    /// The pass succeeded after `attempts` total attempts.
+    fn on_success(&self, _attempts: u32, _summary_chars: usize, _elapsed: Duration) {}
+
+    /// The pass failed terminally after `attempts` total attempts.
+    fn on_error(&self, _attempts: u32) {}
+}
+
+/// No-op observer for tests and harnesses without telemetry.
+impl FullReplaceObserver for () {}