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/codegen/kigi-shell/src/instrumentation.rs

@@ -0,0 +1,63 @@
+//! Shim — see `kigi_log::instrumentation` for the implementation.
+//!
+//! Two pieces stay here:
+//! - The [`instrumentation_timer!`] macro, because it's `#[macro_export]`-ed
+//!   from this crate and call sites spell it `crate::instrumentation_timer!`
+//!   (i.e. `kigi_shell::instrumentation_timer!`). Keeping the macro here
+//!   means downstream callers don't need to be edited.
+//! - [`finalize_and_exit`], because shell needs to log a terminal exit event
+//!   and flush instrumentation before the process exits.
+
+pub use kigi_log::instrumentation::{
+    ChromeTraceOptions, InstrumentationFinalizer, InstrumentationMode, InstrumentationTimer,
+    TARGET, current_mode, finalize, finalizer, generate_chrome_trace, install_panic_hook, layer,
+    timer,
+};
+
+/// Final cleanup before terminating the process.
+///
+/// Logs an exit event, flushes instrumentation guards, and exits with `code`.
+///
+/// Stays in shell so callers can keep calling `kigi_shell::instrumentation::finalize_and_exit`.
+pub fn finalize_and_exit(code: i32) -> ! {
+    let signal_name = match code {
+        130 => "SIGINT",
+        143 => "SIGTERM",
+        _ => "other",
+    };
+    tracing::info!(
+        event_type = "process_exit",
+        signal = signal_name,
+        exit_code = code,
+        "Exiting process"
+    );
+    let _ = finalize();
+    // Flush the --debug firehose; this exits via process::exit, bypassing main's flush.
+    kigi_log::debug_log::flush();
+    std::process::exit(code);
+}
+
+/// Time a block under the instrumentation target.
+///
+/// Macro stays in shell so `$crate` continues to resolve to `kigi_shell`
+/// for the 12+ existing call sites that spell it as
+/// `crate::instrumentation_timer!(...)` or `kigi_shell::instrumentation_timer!(...)`.
+/// The macro body delegates to types and functions in
+/// `kigi_log::instrumentation`.
+#[macro_export]
+macro_rules! instrumentation_timer {
+    ($name:literal) => {{
+        let mode = $crate::instrumentation::current_mode();
+        match mode {
+            $crate::instrumentation::InstrumentationMode::Chrome => {
+                let span = tracing::info_span!(target: $crate::instrumentation::TARGET, $name);
+                $crate::instrumentation::InstrumentationTimer::new_with_span(
+                    $name,
+                    mode,
+                    Some(span.entered()),
+                )
+            }
+            _ => $crate::instrumentation::InstrumentationTimer::new($name),
+        }
+    }};
+}