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/common/kigi-interjection-core/src/buffer.rs

@@ -0,0 +1,75 @@
+use serde::{Deserialize, Serialize};
+
+use crate::events::EventQueue;
+use crate::format::format_interjection;
+
+/// A buffered mid-turn interjection awaiting the next safe drain point.
+/// `Attachment` is host-defined (inline images, asset IDs); core never reads it.
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+pub struct PendingInterjection<Attachment> {
+    pub text: String,
+    pub attachments: Vec<Attachment>,
+}
+
+/// A drained entry, wrapped and ready to emit as a synthetic user message.
+#[derive(Debug, Clone, PartialEq)]
+pub struct FormattedInterjection<Attachment> {
+    pub text: String,
+    pub attachments: Vec<Attachment>,
+}
+
+/// A queue of pending interjections — just an [`EventQueue`] of
+/// [`PendingInterjection`]. Use [`drain_formatted`] to drain + frame them as
+/// synthetic user messages.
+pub type InterjectionBuffer<Attachment> = EventQueue<PendingInterjection<Attachment>>;
+
+/// Drain `buffer`, framing each entry as a synthetic user message (FIFO, one
+/// message per entry, never merged). `sanitize_text` runs on the raw text first
+/// (hosts strip artifacts like image placeholder paths; pass
+/// `std::convert::identity` if none).
+pub fn drain_formatted<Attachment>(
+    buffer: &InterjectionBuffer<Attachment>,
+    sanitize_text: impl Fn(String) -> String,
+) -> Vec<FormattedInterjection<Attachment>> {
+    buffer
+        .drain_all()
+        .into_iter()
+        .map(|entry| FormattedInterjection {
+            text: format_interjection(sanitize_text(entry.text)),
+            attachments: entry.attachments,
+        })
+        .collect()
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn drain_formatted_sanitizes_wraps_and_preserves_order() {
+        let buf: InterjectionBuffer<()> = InterjectionBuffer::new();
+        buf.push(PendingInterjection {
+            text: "look at [SECRET] one".into(),
+            attachments: vec![],
+        });
+        buf.push(PendingInterjection {
+            text: "two".into(),
+            attachments: vec![],
+        });
+
+        let out = drain_formatted(&buf, |t| t.replace("[SECRET] ", ""));
+        assert!(buf.is_empty());
+        assert_eq!(out.len(), 2, "one message per entry, never merged");
+        assert!(
+            out[0]
+                .text
+                .contains("<user_query>\nlook at one\n</user_query>")
+        );
+        assert!(out[1].text.contains("<user_query>\ntwo\n</user_query>"));
+        assert!(
+            out[0]
+                .text
+                .starts_with("The user sent a message while you were working:")
+        );
+    }
+}