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-tui/tests/scenarios/mermaid-affordances.yaml

@@ -0,0 +1,62 @@
+name: mermaid-affordances
+description: >
+  A ```mermaid fence renders inline as Unicode box-drawing art (drawn by the
+  markdown renderer), with a clickable affordance row beneath it led by a dim
+  "◇ mermaid" label ([Open Image] [Copy Image Path] [Copy Source]). Rendering of
+  the full-fidelity PNG is lazy (on click), so no diagram PNG is produced just by
+  detection. The PNG is NEVER transmitted as an inline image, so the treatment is
+  identical in every terminal and no Kitty graphics escape is emitted — asserted
+  against the raw PTY output.
+terminal:
+  rows: 40
+  cols: 100
+mock:
+  response: |
+    Here is a flow:
+
+    ```mermaid
+    flowchart TD
+      A --> B
+      B --> C
+    ```
+
+    Done rendering the flow.
+steps:
+  - action: wait_for_text
+    text: Quit
+    timeout_ms: 20000
+  - action: type_text
+    text: "draw me a diagram"
+  - action: keys
+    keys: "<Enter>"
+  # Mermaid detection runs when the turn finishes, so the affordance row appears
+  # only after the response is complete. Poll for one of its buttons rather than
+  # asserting mid-stream.
+  - action: wait_for_text
+    text: "[Copy Source]"
+    timeout_ms: 30000
+  - action: assert_chat_completion
+  # The fence is rendered inline as Unicode art by the markdown renderer: a TD
+  # flowchart routes forward edges through "▼" arrowheads. Asserting the art (not
+  # the source keyword) confirms the inline diagram replaced the raw source.
+  - action: assert_contains
+    text: "▼"
+  # The full affordance row is plain text: [Open Image] [Copy Image Path] [Copy Source].
+  - action: assert_contains
+    text: "[Open Image]"
+  # The affordance row is led by the dim "◇ mermaid" label.
+  - action: assert_contains
+    text: "◇ mermaid"
+  # Rendering is LAZY: detection alone never dispatches a PNG render, so the row's
+  # transient "rendering diagram…" hint is absent until an [Open Image]/[Copy
+  # Image Path] click. This distinguishes lazy from eager without depending on the
+  # OS clipboard/viewer.
+  - action: assert_not_contains
+    text: "rendering diagram"
+  # The full-fidelity PNG is text + mouse hit-rects only, never an inline image.
+  - action: assert_no_kitty_graphics
+  - action: assert_not_contains
+    text: panicked
+  - action: screenshot
+    name: mermaid-affordances
+    note: Mermaid fence rendered inline as Unicode art with a clickable affordance row.