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-sampler/src/commands.rs

@@ -0,0 +1,47 @@
+//! Internal actor protocol.
+//!
+//! `SamplerCommand` is `pub(crate)` because it is the wire between
+//! [`SamplerHandle`](crate::handle::SamplerHandle) and the actor task,
+//! not a public type. External callers always go through `SamplerHandle`.
+
+use tokio::sync::oneshot;
+
+use kigi_sampling_types::{ConversationRequest, ConversationResponse, SamplingError};
+
+use crate::config::SamplerConfig;
+use crate::metrics::InferenceLatencyStats;
+use crate::types::RequestId;
+
+/// Commands sent from a [`SamplerHandle`](crate::handle::SamplerHandle)
+/// to the actor task.
+///
+/// Large payloads (`ConversationRequest`, `SamplerConfig`) are boxed so
+/// every command stays cheap to copy through the mpsc channel.
+pub(crate) enum SamplerCommand {
+    /// Submit a new sampling request. Fire-and-forget — results come via
+    /// events. When `completion_tx` is set the per-request task also
+    /// signals that channel for `submit_and_collect` callers.
+    Submit {
+        request_id: RequestId,
+        request: Box<ConversationRequest>,
+        config: Option<Box<SamplerConfig>>,
+        completion_tx: Option<
+            oneshot::Sender<Result<(ConversationResponse, InferenceLatencyStats), SamplingError>>,
+        >,
+    },
+
+    /// Cancel an in-flight request.
+    Cancel { request_id: RequestId },
+
+    /// Update the default sampling config (model switch, auth refresh).
+    UpdateConfig { config: Box<SamplerConfig> },
+
+    /// Query: is a specific request still in flight?
+    IsActive {
+        request_id: RequestId,
+        reply: oneshot::Sender<bool>,
+    },
+
+    /// Query: how many requests are in flight?
+    ActiveCount { reply: oneshot::Sender<usize> },
+}