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-pager-pty-harness/src/timing.rs

@@ -0,0 +1,128 @@
+//! Layer 2b: Frame timing via VTE parser.
+//!
+//! Detects frame boundaries from synchronized-update markers
+//! (`CSI ? 2026 h/l`) emitted by crossterm's `BeginSynchronizedUpdate` /
+//! `EndSynchronizedUpdate`, and records wall-clock timing for each frame.
+
+use std::time::{Duration, Instant};
+
+// Use `vte` re-exported from `alacritty_terminal` (via ptyctl) instead of
+// a separate direct dependency.
+use alacritty_terminal::vte;
+
+/// Timing data for a single rendered frame.
+#[derive(Debug, Clone)]
+pub struct FrameTiming {
+    /// Wall-clock duration from BeginSynchronizedUpdate to EndSynchronizedUpdate.
+    pub duration: Duration,
+    /// Number of printable characters emitted within this frame.
+    pub chars: usize,
+}
+
+/// Parses raw PTY output for synchronized-update frame boundaries and
+/// records per-frame timing data.
+///
+/// Composes a `vte::Parser` with an internal `FrameTimingHandler` that
+/// implements `vte::Perform`.
+pub struct FrameTimingParser {
+    vte_parser: vte::Parser,
+    handler: FrameTimingHandler,
+}
+
+impl FrameTimingParser {
+    pub fn new() -> Self {
+        Self {
+            vte_parser: vte::Parser::new(),
+            handler: FrameTimingHandler::new(),
+        }
+    }
+
+    /// Feed raw PTY output bytes, parsing for frame boundaries.
+    pub fn feed(&mut self, bytes: &[u8]) {
+        self.vte_parser.advance(&mut self.handler, bytes);
+    }
+
+    /// Return all recorded frame timings.
+    pub fn timings(&self) -> &[FrameTiming] {
+        &self.handler.timings
+    }
+
+    /// Return the total number of completed frames.
+    pub fn frame_count(&self) -> u64 {
+        self.handler.timings.len() as u64
+    }
+
+    /// Reset all recorded timing data.
+    pub fn reset(&mut self) {
+        self.handler.timings.clear();
+        self.handler.frame_start = None;
+        self.handler.current_frame_chars = 0;
+    }
+}
+
+impl Default for FrameTimingParser {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+/// Internal VTE `Perform` implementation that detects frame boundaries.
+struct FrameTimingHandler {
+    frame_start: Option<Instant>,
+    timings: Vec<FrameTiming>,
+    current_frame_chars: usize,
+}
+
+impl FrameTimingHandler {
+    fn new() -> Self {
+        Self {
+            frame_start: None,
+            timings: Vec::new(),
+            current_frame_chars: 0,
+        }
+    }
+}
+
+impl vte::Perform for FrameTimingHandler {
+    fn csi_dispatch(
+        &mut self,
+        params: &vte::Params,
+        intermediates: &[u8],
+        _ignore: bool,
+        action: char,
+    ) {
+        // Only interested in CSI ? <param> h/l (private mode set/reset).
+        if intermediates != b"?" {
+            return;
+        }
+        let param_val: u16 = params
+            .iter()
+            .next()
+            .and_then(|p| p.first().copied())
+            .unwrap_or(0);
+
+        if param_val == 2026 {
+            match action {
+                'h' => {
+                    // BeginSynchronizedUpdate: frame starts.
+                    self.frame_start = Some(Instant::now());
+                    self.current_frame_chars = 0;
+                }
+                'l' => {
+                    // EndSynchronizedUpdate: frame ends.
+                    if let Some(start) = self.frame_start.take() {
+                        self.timings.push(FrameTiming {
+                            duration: start.elapsed(),
+                            chars: self.current_frame_chars,
+                        });
+                    }
+                }
+                _ => {}
+            }
+        }
+    }
+
+    fn print(&mut self, _c: char) {
+        self.current_frame_chars += 1;
+    }
+}