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-pager-render/src/terminal/probe.rs

@@ -0,0 +1,159 @@
+//! Shared startup terminal-probe primitive: write a query, and (OSC 11
+//! only) raw-fd poll/read stdin until a terminator or deadline.
+//! XTVERSION uses only `write_query`;
+//! its reply is handled by the event loop's response filter.
+//!
+//! Safety invariants (timed-read path):
+//! - Startup-only: must run before crossterm's `EventStream` exists (both
+//!   compete for stdin).
+//! - Keystrokes typed inside the read window are consumed and dropped — no
+//!   portable re-injection exists (TIOCSTI is blocked); accepted loss.
+
+use std::io::Write;
+use std::time::Duration;
+
+/// Bounds the reply buffer against terminals that stream without a terminator.
+#[cfg(unix)]
+pub(crate) const MAX_PROBE_RESPONSE: usize = 256;
+
+/// Hard cap on post-deadline consumption of an in-flight reply.
+#[cfg(unix)]
+const LATE_REPLY_GRACE: Duration = Duration::from_millis(100);
+
+/// Per-byte quiet window during the grace period.
+#[cfg(unix)]
+const LATE_REPLY_QUIET_MS: i32 = 25;
+
+/// Write a probe query via the shared stderr lock; `false` if the TUI fd is
+/// not a TTY or the write fails.
+pub(crate) fn write_query(query: &[u8]) -> bool {
+    use std::io::IsTerminal;
+
+    let write_result: std::io::Result<()> = kigi_shared::stderr::with_locked_stderr(|stderr| {
+        // fd 2 is /dev/null-redirected; the TTY check must run on the
+        // dup'd render fd inside the lock, not on std::io::stderr().
+        if !stderr.is_terminal() {
+            return Err(std::io::Error::other("TUI output is not a TTY"));
+        }
+        stderr.write_all(query)?;
+        stderr.flush()
+    });
+    write_result.is_ok()
+}
+
+/// Read stdin until `is_terminated`, the size cap, or the deadline.
+///
+/// Returns `Some(buf)` whenever bytes were consumed (even partial, so a
+/// half-read reply is never left for the EventStream); `None` when nothing
+/// arrived or stdin errored before any byte.
+#[cfg(unix)]
+pub(crate) fn read_tty_reply(
+    timeout: Duration,
+    mut is_terminated: impl FnMut(&[u8], u8) -> bool,
+) -> Option<Vec<u8>> {
+    use std::os::unix::io::AsRawFd;
+
+    let fd = std::io::stdin().as_raw_fd();
+    let start = std::time::Instant::now();
+    let mut buf: Vec<u8> = Vec::with_capacity(64);
+
+    loop {
+        let Some(remaining) = timeout.checked_sub(start.elapsed()) else {
+            return finish_after_deadline(fd, buf, is_terminated);
+        };
+        let remaining_ms = remaining.as_millis().min(i32::MAX as u128) as i32;
+
+        match poll_read_byte(fd, remaining_ms) {
+            PollRead::Byte(byte) => {
+                buf.push(byte);
+                if buf.len() >= MAX_PROBE_RESPONSE || is_terminated(&buf, byte) {
+                    return Some(buf);
+                }
+            }
+            // Re-entry recomputes the deadline, so EINTR cannot extend it.
+            PollRead::Interrupted => continue,
+            PollRead::Timeout => return finish_after_deadline(fd, buf, is_terminated),
+            PollRead::Error => return if buf.is_empty() { None } else { Some(buf) },
+        }
+    }
+}
+
+/// Deadline expiry: an in-flight reply (ESC byte seen — replies are
+/// DCS/CSI/OSC, plain keystrokes aren't) is consumed until quiet so its
+/// tail can't reach the EventStream as typed garbage; otherwise return
+/// immediately to avoid eating keystrokes at a silent terminal.
+#[cfg(unix)]
+fn finish_after_deadline(
+    fd: i32,
+    mut buf: Vec<u8>,
+    mut is_terminated: impl FnMut(&[u8], u8) -> bool,
+) -> Option<Vec<u8>> {
+    if buf.is_empty() {
+        return None;
+    }
+    if !buf.contains(&0x1b) {
+        return Some(buf);
+    }
+    let grace_start = std::time::Instant::now();
+    while grace_start.elapsed() < LATE_REPLY_GRACE {
+        match poll_read_byte(fd, LATE_REPLY_QUIET_MS) {
+            PollRead::Byte(byte) => {
+                buf.push(byte);
+                if buf.len() >= MAX_PROBE_RESPONSE || is_terminated(&buf, byte) {
+                    break;
+                }
+            }
+            PollRead::Interrupted => continue,
+            PollRead::Timeout | PollRead::Error => break,
+        }
+    }
+    Some(buf)
+}
+
+#[cfg(unix)]
+enum PollRead {
+    Byte(u8),
+    Interrupted,
+    Timeout,
+    Error,
+}
+
+/// One EINTR-retrying poll-then-read step for a single byte.
+#[cfg(unix)]
+fn poll_read_byte(fd: i32, timeout_ms: i32) -> PollRead {
+    let mut pfd = libc::pollfd {
+        fd,
+        events: libc::POLLIN,
+        revents: 0,
+    };
+    // SAFETY: pfd is a valid pollfd struct with a valid fd.
+    let ret = unsafe { libc::poll(&mut pfd, 1, timeout_ms) };
+    if ret == 0 {
+        return PollRead::Timeout;
+    }
+    if ret < 0 {
+        return if last_errno_is_eintr() {
+            PollRead::Interrupted
+        } else {
+            PollRead::Error
+        };
+    }
+
+    loop {
+        let mut byte = [0u8; 1];
+        // SAFETY: byte is a valid buffer of length 1.
+        let n = unsafe { libc::read(fd, byte.as_mut_ptr().cast(), 1) };
+        if n == 1 {
+            return PollRead::Byte(byte[0]);
+        }
+        if n < 0 && last_errno_is_eintr() {
+            continue;
+        }
+        return PollRead::Error;
+    }
+}
+
+#[cfg(unix)]
+fn last_errno_is_eintr() -> bool {
+    std::io::Error::last_os_error().raw_os_error() == Some(libc::EINTR)
+}