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/overlay.rs

@@ -0,0 +1,301 @@
+use std::io::{self, Write};
+use std::sync::atomic::{AtomicU64, Ordering};
+
+use ratatui::layout::Rect;
+
+use super::image::{
+    GraphicsProtocol, KITTY_PLACEMENT_ID, build_overlay_image_escapes_for_protocol,
+    clear_kitty_image, detect_graphics_protocol, fit_image_to_cells,
+};
+
+static NEXT_OWNER_ID: AtomicU64 = AtomicU64::new(1);
+
+thread_local! {
+    static OWNER: std::cell::Cell<Option<u64>> = const { std::cell::Cell::new(None) };
+}
+
+#[derive(Clone, Copy, Debug, Eq, PartialEq)]
+pub(crate) enum Ownership {
+    Static(u64),
+    Clear,
+}
+
+#[derive(Debug)]
+pub struct Escapes {
+    bytes: String,
+    ownership: Ownership,
+}
+
+impl Escapes {
+    pub fn as_str(&self) -> &str {
+        &self.bytes
+    }
+
+    pub fn into_string(self) -> String {
+        self.bytes
+    }
+
+    pub fn commit(self) -> String {
+        commit(self.ownership);
+        self.bytes
+    }
+}
+
+#[derive(Debug, Default)]
+pub struct PostFlush {
+    bytes: String,
+    ownership: Option<Ownership>,
+}
+
+impl PostFlush {
+    pub fn plain(bytes: String) -> Self {
+        Self {
+            bytes,
+            ownership: None,
+        }
+    }
+
+    pub fn append(&mut self, other: Self) {
+        self.bytes.push_str(&other.bytes);
+        if let Some(ownership) = other.ownership {
+            self.ownership = Some(ownership);
+        }
+    }
+
+    pub fn append_plain(&mut self, bytes: &str) {
+        self.bytes.push_str(bytes);
+    }
+
+    pub fn as_str(&self) -> &str {
+        &self.bytes
+    }
+
+    pub fn write_to(self, writer: &mut impl Write) -> io::Result<()> {
+        writer.write_all(self.bytes.as_bytes())?;
+        if let Some(ownership) = self.ownership {
+            commit(ownership);
+        }
+        Ok(())
+    }
+}
+
+impl From<Escapes> for PostFlush {
+    fn from(escapes: Escapes) -> Self {
+        Self {
+            bytes: escapes.bytes,
+            ownership: Some(escapes.ownership),
+        }
+    }
+}
+
+pub(crate) fn next_owner_id() -> u64 {
+    NEXT_OWNER_ID.fetch_add(1, Ordering::Relaxed)
+}
+
+pub fn reset_owner() {
+    OWNER.with(|owner| owner.set(None));
+}
+
+fn commit(ownership: Ownership) {
+    OWNER.with(|owner| {
+        owner.set(match ownership {
+            Ownership::Static(id) => Some(id),
+            Ownership::Clear => None,
+        });
+    });
+}
+
+#[allow(clippy::too_many_arguments)]
+pub(crate) fn static_image_for_protocol(
+    protocol: GraphicsProtocol,
+    image_data: &[u8],
+    cols: u16,
+    rows: u16,
+    cell_x: u16,
+    cell_y: u16,
+    owner_id: u64,
+) -> Option<Escapes> {
+    let retransmit = OWNER.with(|owner| owner.get() != Some(owner_id));
+    let bytes = build_overlay_image_escapes_for_protocol(
+        protocol, image_data, cols, rows, cell_x, cell_y, retransmit,
+    )?;
+    Some(Escapes {
+        bytes,
+        ownership: Ownership::Static(owner_id),
+    })
+}
+
+#[allow(clippy::too_many_arguments)]
+pub fn static_image(
+    image_data: &[u8],
+    cols: u16,
+    rows: u16,
+    cell_x: u16,
+    cell_y: u16,
+    owner_id: u64,
+) -> Option<Escapes> {
+    static_image_for_protocol(
+        detect_graphics_protocol(),
+        image_data,
+        cols,
+        rows,
+        cell_x,
+        cell_y,
+        owner_id,
+    )
+}
+
+pub fn volatile_image(
+    image_data: &[u8],
+    cols: u16,
+    rows: u16,
+    cell_x: u16,
+    cell_y: u16,
+) -> Option<Escapes> {
+    let bytes = build_overlay_image_escapes_for_protocol(
+        detect_graphics_protocol(),
+        image_data,
+        cols,
+        rows,
+        cell_x,
+        cell_y,
+        true,
+    )?;
+    Some(Escapes {
+        bytes,
+        ownership: Ownership::Clear,
+    })
+}
+
+pub fn static_centered(
+    image_data: &[u8],
+    img_w: u32,
+    img_h: u32,
+    overlay_rect: Rect,
+    owner_id: u64,
+) -> Option<Escapes> {
+    let (cols, rows, x, y) = centered_placement(img_w, img_h, overlay_rect)?;
+    static_image(image_data, cols, rows, x, y, owner_id)
+}
+
+pub fn volatile_centered(
+    image_data: &[u8],
+    img_w: u32,
+    img_h: u32,
+    overlay_rect: Rect,
+) -> Option<Escapes> {
+    let (cols, rows, x, y) = centered_placement(img_w, img_h, overlay_rect)?;
+    volatile_image(image_data, cols, rows, x, y)
+}
+
+pub fn clear() -> Option<Escapes> {
+    match detect_graphics_protocol() {
+        GraphicsProtocol::Kitty => Some(clear_kitty()),
+        GraphicsProtocol::ITerm2 | GraphicsProtocol::None => None,
+    }
+}
+
+pub fn clear_kitty() -> Escapes {
+    Escapes {
+        bytes: clear_kitty_image(KITTY_PLACEMENT_ID),
+        ownership: Ownership::Clear,
+    }
+}
+
+fn centered_placement(img_w: u32, img_h: u32, overlay_rect: Rect) -> Option<(u16, u16, u16, u16)> {
+    let max_cols = overlay_rect.width.saturating_sub(2);
+    let max_rows = overlay_rect.height.saturating_sub(2);
+    if max_cols < 4 || max_rows < 2 {
+        return None;
+    }
+    let (cols, rows) = fit_image_to_cells(img_w, img_h, max_cols, max_rows);
+    let x = overlay_rect.x + 1 + max_cols.saturating_sub(cols) / 2;
+    let y = overlay_rect.y + 1 + max_rows.saturating_sub(rows) / 2;
+    Some((cols, rows, x, y))
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::terminal::image::set_protocol_for_test;
+
+    fn png() -> [u8; 8] {
+        [0x89, b'P', b'N', b'G', b'\r', b'\n', 0x1a, b'\n']
+    }
+
+    #[test]
+    fn static_owner_reuses_consecutive_frames_after_commit() {
+        let _guard = set_protocol_for_test(GraphicsProtocol::Kitty);
+        reset_owner();
+        let first = static_image(&png(), 20, 10, 0, 0, 11).unwrap();
+        assert!(first.as_str().contains("a=t"));
+        let _ = first.commit();
+        let second = static_image(&png(), 20, 10, 0, 0, 11).unwrap();
+        assert!(!second.as_str().contains("a=t"));
+    }
+
+    #[test]
+    fn discarded_clear_does_not_invalidate_static_owner() {
+        let _guard = set_protocol_for_test(GraphicsProtocol::Kitty);
+        reset_owner();
+        let _ = static_image(&png(), 20, 10, 0, 0, 11).unwrap().commit();
+        let _discarded = clear().unwrap();
+        let next = static_image(&png(), 20, 10, 0, 0, 11).unwrap();
+        assert!(!next.as_str().contains("a=t"));
+    }
+
+    #[test]
+    fn discarded_static_escape_does_not_replace_owner() {
+        let _guard = set_protocol_for_test(GraphicsProtocol::Kitty);
+        reset_owner();
+        let _ = static_image(&png(), 20, 10, 0, 0, 11).unwrap().commit();
+        let _discarded = static_image(&png(), 20, 10, 0, 0, 12).unwrap();
+        let next = static_image(&png(), 20, 10, 0, 0, 11).unwrap();
+        assert!(!next.as_str().contains("a=t"));
+    }
+
+    #[test]
+    fn failed_post_flush_write_does_not_commit_transition() {
+        struct FailingWriter;
+
+        impl std::io::Write for FailingWriter {
+            fn write(&mut self, _buf: &[u8]) -> std::io::Result<usize> {
+                Err(std::io::Error::other("injected write failure"))
+            }
+
+            fn flush(&mut self) -> std::io::Result<()> {
+                Ok(())
+            }
+        }
+
+        let _guard = set_protocol_for_test(GraphicsProtocol::Kitty);
+        reset_owner();
+        let _ = static_image(&png(), 20, 10, 0, 0, 11).unwrap().commit();
+        let clear = PostFlush::from(clear().unwrap());
+        assert!(clear.write_to(&mut FailingWriter).is_err());
+        let next = static_image(&png(), 20, 10, 0, 0, 11).unwrap();
+        assert!(!next.as_str().contains("a=t"));
+    }
+
+    #[test]
+    fn committed_clear_and_volatile_frame_invalidate_owner() {
+        let _guard = set_protocol_for_test(GraphicsProtocol::Kitty);
+        reset_owner();
+        let _ = static_image(&png(), 20, 10, 0, 0, 11).unwrap().commit();
+        let _ = clear().unwrap().commit();
+        assert!(
+            static_image(&png(), 20, 10, 0, 0, 11)
+                .unwrap()
+                .as_str()
+                .contains("a=t")
+        );
+        let _ = static_image(&png(), 20, 10, 0, 0, 11).unwrap().commit();
+        let _ = volatile_image(&png(), 20, 10, 0, 0).unwrap().commit();
+        assert!(
+            static_image(&png(), 20, 10, 0, 0, 11)
+                .unwrap()
+                .as_str()
+                .contains("a=t")
+        );
+    }
+}