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-file-utils/src/lib.rs

@@ -0,0 +1,84 @@
+//! Local file utilities: per-turn event tracking, content hashing, and
+//! project-directory classification.
+pub mod events;
+pub mod s3;
+pub mod trace_context;
+pub mod workspace_classifier;
+
+/// Directory names that are always skipped when scanning a workspace for
+/// project content (dependency caches, build output, editor state, …).
+pub const SKIP_DIR_NAMES: &[&str] = &[
+    "node_modules",
+    "__pycache__",
+    ".venv",
+    "venv",
+    "env",
+    ".env",
+    "target",
+    "dist",
+    "build",
+    "out",
+    ".next",
+    ".nuxt",
+    ".output",
+    ".cache",
+    ".parcel-cache",
+    ".turbo",
+    "vendor",
+    "bower_components",
+    ".tox",
+    ".nox",
+    ".eggs",
+    ".idea",
+    ".vscode",
+    ".gradle",
+    ".dart_tool",
+    "coverage",
+    ".nyc_output",
+    "htmlcov",
+    ".pytest_cache",
+    ".mypy_cache",
+    ".ruff_cache",
+];
+
+/// [`SKIP_DIR_NAMES`] as a set for O(1) membership checks.
+pub fn skip_dir_set() -> &'static std::collections::HashSet<&'static str> {
+    use std::collections::HashSet;
+    use std::sync::LazyLock;
+    static SET: LazyLock<HashSet<&str>> =
+        LazyLock::new(|| SKIP_DIR_NAMES.iter().copied().collect());
+    &SET
+}
+
+/// Compute SHA256 hash of content as a hex string.
+pub fn sha256_hex(content: &[u8]) -> String {
+    use sha2::{Digest, Sha256};
+    let mut hasher = Sha256::new();
+    hasher.update(content);
+    format!("{:x}", hasher.finalize())
+}
+/// Compute SHA256 hash of a file by streaming, without loading entire file into memory.
+/// If `max_bytes` is set (> 0), only hash up to that many bytes.
+pub fn sha256_hex_from_file(
+    path: &std::path::Path,
+    max_bytes: Option<u64>,
+) -> std::io::Result<String> {
+    use sha2::{Digest, Sha256};
+    use std::io::Read;
+    let file = std::fs::File::open(path)?;
+    let mut reader: Box<dyn Read> = if let Some(limit) = max_bytes {
+        Box::new(file.take(limit))
+    } else {
+        Box::new(file)
+    };
+    let mut hasher = Sha256::new();
+    let mut buffer = [0u8; 8192];
+    loop {
+        let bytes_read = reader.read(&mut buffer)?;
+        if bytes_read == 0 {
+            break;
+        }
+        hasher.update(&buffer[..bytes_read]);
+    }
+    Ok(format!("{:x}", hasher.finalize()))
+}