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-fast-worktree/src/worktree/plan.rs

@@ -0,0 +1,64 @@
+//! Worktree execution planning.
+//!
+//! `WorktreePlan` makes the worktree creation pipeline explicit and testable.
+
+use std::path::PathBuf;
+use std::sync::Arc;
+
+use tokio_util::sync::CancellationToken;
+
+use crate::{BtrfsDelegate, CreationMode, IgnoredFilesMode, WorkingTreeMode};
+
+#[derive(Clone)]
+pub(crate) struct WorktreePlan {
+    // Note: manual Debug impl below (Arc<dyn BtrfsDelegate> isn't Debug)
+    pub source: PathBuf,
+    pub dest: PathBuf,
+    pub git_ref: String,
+    pub parallelism: usize,
+    pub channel_buffer: usize,
+    pub working_tree: WorkingTreeMode,
+    pub ignored_files: IgnoredFilesMode,
+    pub ignored_parallelism: usize,
+    /// Strategy for worktree creation (linked, standalone, or git checkout).
+    pub creation_mode: CreationMode,
+    /// Cancellation token for aborting file copy mid-flight.
+    pub cancellation_token: CancellationToken,
+    /// Optional delegate for privileged btrfs operations (used when the caller
+    /// lacks CAP_SYS_ADMIN, e.g., inside a bwrap sandbox).
+    /// Only read on Linux (in `try_btrfs_delegate`).
+    #[cfg_attr(not(target_os = "linux"), allow(dead_code))]
+    pub btrfs_delegate: Option<Arc<dyn BtrfsDelegate>>,
+}
+
+impl std::fmt::Debug for WorktreePlan {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.debug_struct("WorktreePlan")
+            .field("source", &self.source)
+            .field("dest", &self.dest)
+            .field("git_ref", &self.git_ref)
+            .field("parallelism", &self.parallelism)
+            .field("working_tree", &self.working_tree)
+            .field("creation_mode", &self.creation_mode)
+            .field("has_btrfs_delegate", &self.btrfs_delegate.is_some())
+            .finish()
+    }
+}
+
+impl WorktreePlan {
+    pub(crate) fn effective_parallelism(&self) -> usize {
+        if self.parallelism == 0 {
+            num_cpus::get()
+        } else {
+            self.parallelism
+        }
+    }
+
+    pub(crate) fn effective_ignored_parallelism(&self) -> usize {
+        if self.ignored_parallelism == 0 {
+            num_cpus::get()
+        } else {
+            self.ignored_parallelism
+        }
+    }
+}