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-tools/src/util/env.rs

@@ -0,0 +1,81 @@
+//! Environment variable helpers and process isolation for terminal execution.
+//!
+//! All implementations now live in the lightweight [`kigi_tty_utils`] crate
+//! so that every crate in the workspace can use them without pulling in the
+//! heavyweight `kigi-tools` dependency. This module re-exports the public
+//! API for backward compatibility.
+
+pub use kigi_tty_utils::{detach_from_tty, pager_env};
+
+/// Env var set on agent-spawned terminal processes so host tools (e.g. `x ban`)
+/// can distinguish agent invocations from human interactive shells.
+/// Note: the CLI also uses `KIGI_AGENT` as an
+/// optional agent-definition selector for launching `grok` itself; child terminal
+/// processes only need the sentinel value `"1"`.
+pub const KIGI_AGENT_ENV: &str = "KIGI_AGENT";
+
+/// Sentinel value for [`KIGI_AGENT_ENV`] on agent tool terminals.
+pub const KIGI_AGENT_ENV_VALUE: &str = "1";
+
+/// Force `KIGI_AGENT=1` on an agent terminal child so request/login env cannot
+/// clear the agent marker.
+pub fn apply_grok_agent_marker(cmd: &mut tokio::process::Command) {
+    cmd.env(KIGI_AGENT_ENV, KIGI_AGENT_ENV_VALUE);
+}
+
+/// Expand the four plugin-path tokens (`${CLAUDE_PLUGIN_ROOT}` / `${KIGI_PLUGIN_ROOT}`
+/// and `${CLAUDE_PLUGIN_DATA}` / `${KIGI_PLUGIN_DATA}`) in `s`. Each pair is expanded
+/// only when its value is provided. Single source of truth for plugin agent bodies,
+/// plugin skill/command bodies, and plugin MCP/hook config substitution.
+pub fn substitute_plugin_tokens(
+    s: &str,
+    plugin_root: Option<&str>,
+    plugin_data: Option<&str>,
+) -> String {
+    let mut out = s.to_string();
+    if let Some(root) = plugin_root {
+        out = out
+            .replace("${CLAUDE_PLUGIN_ROOT}", root)
+            .replace("${KIGI_PLUGIN_ROOT}", root);
+    }
+    if let Some(data) = plugin_data {
+        out = out
+            .replace("${CLAUDE_PLUGIN_DATA}", data)
+            .replace("${KIGI_PLUGIN_DATA}", data);
+    }
+    out
+}
+
+#[cfg(test)]
+mod tests {
+    use super::{KIGI_AGENT_ENV, KIGI_AGENT_ENV_VALUE, substitute_plugin_tokens};
+
+    const ALL_TOKENS: &str = "${CLAUDE_PLUGIN_ROOT}/a ${KIGI_PLUGIN_ROOT}/b ${CLAUDE_PLUGIN_DATA}/c ${KIGI_PLUGIN_DATA}/d";
+
+    #[test]
+    fn expands_all_four_tokens_when_both_provided() {
+        let out = substitute_plugin_tokens(ALL_TOKENS, Some("/root"), Some("/data"));
+        assert_eq!(out, "/root/a /root/b /data/c /data/d");
+    }
+
+    #[test]
+    fn leaves_tokens_literal_when_both_none() {
+        let out = substitute_plugin_tokens(ALL_TOKENS, None, None);
+        assert_eq!(out, ALL_TOKENS);
+    }
+
+    #[test]
+    fn expands_only_root_when_data_none() {
+        let out = substitute_plugin_tokens(ALL_TOKENS, Some("/root"), None);
+        assert_eq!(
+            out,
+            "/root/a /root/b ${CLAUDE_PLUGIN_DATA}/c ${KIGI_PLUGIN_DATA}/d"
+        );
+    }
+
+    #[test]
+    fn agent_marker_constants_match_cursor_parity() {
+        assert_eq!(KIGI_AGENT_ENV, "KIGI_AGENT");
+        assert_eq!(KIGI_AGENT_ENV_VALUE, "1");
+    }
+}