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-tui/tests/leader_pty_e2e/common.rs

@@ -0,0 +1,44 @@
+//! Shared constants for the leader-mode PTY e2e tests.
+//!
+//! Drive/seed helpers live in `kigi_pager_pty_harness::flows` (one
+//! canonical copy shared with `pty_e2e`); only suite-local constants stay
+//! here.
+
+pub(crate) use kigi_pager_pty_harness::{
+    ContentController, LeaderCluster, MockModel, PtyHarness, inference_request_count, keys,
+    oauth_env_for_pager, pager_binary, seed_fake_oauth, submit_turn, wait_for_labels_absent,
+    wait_for_model_via_new_sessions,
+};
+pub(crate) use serde_json::json;
+pub(crate) use std::time::{Duration, Instant};
+
+/// Default PTY size used by every e2e test (same as `pty_e2e`).
+pub(crate) const DEFAULT_ROWS: u16 = 50;
+
+pub(crate) const DEFAULT_COLS: u16 = 120;
+
+/// Substring we wait for on the welcome screen (matches the menu label).
+pub(crate) const WELCOME_SCREEN_SENTINEL: &str = "Quit";
+
+/// Prompt sent to the agent in content-driven tests.
+pub(crate) const PROMPT: &str = "go";
+
+/// Response sentinel the mock server streams back.
+pub(crate) const MOCK_RESPONSE_SENTINEL: &str = "MOCKRESPONSE";
+
+/// Cold leader-client bring-up budget. History: 60s → 120s → 240s while these
+/// cases ran interleaved with the full `pty_e2e` suite (each leader case
+/// spawns multiple full pager processes; suite-wide contention pushed cold
+/// bring-up past two minutes). Now that the leader cases run in their own
+/// serialized target the budget can come back down after a green soak week —
+/// tracked in the leader test-infra plan.
+pub(crate) const LEADER_TIMEOUT: Duration = Duration::from_secs(240);
+
+/// Streamed-turn deadline in leader mode (same contention rationale).
+pub(crate) const STREAM_TIMEOUT: Duration = Duration::from_secs(120);
+
+/// Sentinel for leader-test turn `n`, short enough to never wrap at 120 cols
+/// (wrapping would break the exactly-once occurrence counts).
+pub(crate) fn turn_sentinel(n: u8) -> String {
+    format!("{MOCK_RESPONSE_SENTINEL}_T{n}")
+}