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-log/src/hooks_log.rs

@@ -0,0 +1,123 @@
+//! Hooks and plugins tracing target and optional file-based logging layer.
+//!
+//! A dedicated tracing target for hooks and plugins subsystems with an optional
+//! file logger that writes to `~/.kigi/logs/hooks.log`.
+//!
+//! ## When to use
+//!
+//! Use regular `tracing::info!` / `tracing::debug!` / `tracing::warn!` with
+//! targets `kigi_hooks` or `kigi_agent::plugins` at key lifecycle
+//! points — discovery, dispatch, execution, errors.
+//!
+//! ## Enabling
+//!
+//! ```bash
+//! KIGI_HOOKS_LOG=1 grok              # enable, write to ~/.kigi/logs/hooks.log
+//! KIGI_HOOKS_LOG=/tmp/h.log grok     # write to custom path
+//! KIGI_HOOKS_LOG=0 grok              # explicitly disable
+//! tail -f ~/.kigi/logs/hooks.log     # watch in another terminal
+//! ```
+
+use std::fmt;
+use std::path::PathBuf;
+use std::sync::Mutex;
+use std::time::Instant;
+
+use tracing::Subscriber;
+use tracing_subscriber::fmt::format::Writer;
+use tracing_subscriber::fmt::time::FormatTime;
+use tracing_subscriber::fmt::writer::BoxMakeWriter;
+use tracing_subscriber::layer::Layer;
+use tracing_subscriber::registry::LookupSpan;
+
+use kigi_config::kigi_home;
+
+const ENV_HOOKS_LOG: &str = "KIGI_HOOKS_LOG";
+
+static LOG_GUARD: std::sync::OnceLock<Mutex<Option<tracing_appender::non_blocking::WorkerGuard>>> =
+    std::sync::OnceLock::new();
+
+#[derive(Clone)]
+struct UptimeTimer {
+    epoch: Instant,
+}
+
+impl UptimeTimer {
+    fn new() -> Self {
+        Self {
+            epoch: Instant::now(),
+        }
+    }
+}
+
+impl FormatTime for UptimeTimer {
+    fn format_time(&self, w: &mut Writer<'_>) -> fmt::Result {
+        let elapsed = self.epoch.elapsed();
+        write!(w, "+{}.{:03}s", elapsed.as_secs(), elapsed.subsec_millis())
+    }
+}
+
+/// Build the hooks/plugins log layer.
+///
+/// Writes to `~/.kigi/logs/hooks.log` (or custom path via `KIGI_HOOKS_LOG`).
+/// Filters to hooks (`kigi_hooks`) and plugins (`kigi_agent::plugins`) targets.
+/// Set `KIGI_HOOKS_LOG=0` to disable, `KIGI_HOOKS_LOG=/path` to redirect.
+pub fn layer<S>() -> Option<impl Layer<S>>
+where
+    S: Subscriber + for<'span> LookupSpan<'span>,
+{
+    let path = resolve_log_path()?;
+
+    if let Some(parent) = path.parent() {
+        let _ = std::fs::create_dir_all(parent);
+    }
+
+    let file = match std::fs::OpenOptions::new()
+        .create(true)
+        .append(true)
+        .open(&path)
+    {
+        Ok(f) => f,
+        Err(e) => {
+            tracing::warn!("[hooks-log] Failed to open {:?}: {}", path, e);
+            return None;
+        }
+    };
+
+    let (non_blocking, guard) = tracing_appender::non_blocking(file);
+    let guard_slot = LOG_GUARD.get_or_init(|| Mutex::new(None));
+    if let Ok(mut slot) = guard_slot.lock() {
+        *slot = Some(guard);
+    }
+
+    // Filter for both hooks and plugins targets at debug level
+    let filter =
+        tracing_subscriber::filter::EnvFilter::new("kigi_hooks=debug,kigi_agent::plugins=debug");
+    let fmt_layer = tracing_subscriber::fmt::layer()
+        .with_target(true)
+        .with_ansi(false)
+        .with_thread_ids(true)
+        .with_timer(UptimeTimer::new())
+        .with_writer(BoxMakeWriter::new(non_blocking))
+        .with_filter(filter);
+
+    tracing::info!(
+        "[hooks-log] Hooks/plugins logging enabled: {}",
+        path.display()
+    );
+    Some(fmt_layer)
+}
+
+fn resolve_log_path() -> Option<PathBuf> {
+    let default_path = || kigi_home().join("logs").join("hooks.log");
+    let raw = match std::env::var(ENV_HOOKS_LOG) {
+        Ok(val) => val,
+        Err(_) => return None, // opt-in only
+    };
+    let raw = raw.trim();
+    match raw {
+        "" | "0" | "false" | "off" | "no" => None,
+        "1" | "true" | "on" | "yes" => Some(default_path()),
+        other => Some(PathBuf::from(other)),
+    }
+}