chore(v0.8.8): stabilization batch — sub-agent caps, mutex contention, RLM polish, CI cleanup

Bundles the v0.8.8 stabilization fixes that were already implemented in the
working tree, plus the workflow/doc reconciliation called out in #507.

### Sub-agent runtime fixes
- **#509** Default sub-agent cap raised to 10 (configurable via
  `[subagents].max_concurrent` in `config.toml`, hard ceiling 20). The
  running-count calculation now ignores non-running, no-handle, and finished
  handles so completed agents stop counting against the cap.
- **#510** `SharedSubAgentManager` is now `Arc<RwLock<...>>`; the read paths
  that previously held a `Mutex` for inspection now take a read lock,
  eliminating the multi-agent fan-out UI freeze.
- **#511** `compact_tool_result_for_context` summarizes `agent_result` /
  `agent_wait` payloads before they are folded into the parent context.
- **#512** RLM tool cards map to `ToolFamily::Rlm` and render `rlm`, not
  `swarm`. Stale "swarm" wording cleaned in docs/comments/tests.
- **#513** (foreground stopgap only) Foreground RLM work is visible in the
  Agents sidebar projection. Full async RLM lifecycle remains v0.8.9 — the
  issue stays open with a refined scope.

### TUI / UX fixes
- **#487** Offline composer queue is now session-scoped; legacy unscoped
  queues fail closed.
- **#488** Composer Option+Backspace deletes by word; cross-platform key
  routing helpers added.
- **#443/#444** Keyboard enhancement flags pop on normal AND panic exit; the
  raw-mode startup probe is now bounded by a configurable timeout.
- **#449** Production footer reads statusline colors from `app.ui_theme`
  rather than the bespoke palette.
- **#506** `display_path_with_home` no longer mutates `HOME` in tests; the
  flake on shared-env CI is gone.

### Self-update / packaging
- **#503** `update.rs` arch mapping uses release-asset naming (`arm64`/`x64`)
  instead of the raw Rust constants. The platform-asset selector also rejects
  `.sha256` siblings as primary binaries. Tests now live alongside the source
  in `mod tests` (the `#[path]`-based integration test was removed because it
  duplicated test runs and forced a `pub(crate)` helper that no real caller
  used).
- **`Max 5 in flight` wording updated** in `agent_spawn` description,
  `prompts/base.md`, and `docs/TOOL_SURFACE.md` so the model sees the real
  default cap (10) and the configuration knob name.

### CI / release docs (#507)
- Pruned three duplicated/dead workflows: `crates-publish.yml`, `parity.yml`,
  `publish-npm.yml`. Their gates already run in `ci.yml` for every push/PR.
- `release.yml` build job now allows `parity` to be skipped (it only runs on
  tag push), unblocking `workflow_dispatch` reruns. The job still fails
  closed on a real parity failure.
- `RELEASE_RUNBOOK.md` reconciled: crate publishing is documented as the
  manual `scripts/release/publish-crates.sh` flow (no automated workflow);
  references to the deleted workflows removed.
- `CLAUDE.md` notes the `RELEASE_TAG_PAT` requirement for the auto-tag →
  release.yml chain (without it, the tag is created but `release.yml` does
  not fire) and documents the `workflow_dispatch` parity-skip behavior.

### Docs
- `docs/COMPETITIVE_ANALYSIS.md` added — capability matrix vs OpenCode and
  Codex CLI, gap analysis, and recommended implementation order.

### Verification (this branch)
- `cargo fmt --all -- --check` ✓
- `cargo check --workspace --all-targets --locked` ✓
- `cargo clippy --workspace --all-targets --all-features --locked -- -D warnings` ✓
- `cargo test --workspace --all-features --locked` ✓ (1809 + supporting)
- Parity gates ✓ (snapshot, parity_protocol, parity_state)
- `cargo build --release --locked -p deepseek-tui-cli -p deepseek-tui` ✓
- Lockfile drift guard ✓
- `deepseek doctor --json` clean
- `deepseek eval` (offline harness) success=true, 0 tool errors

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

.github/workflows/ci.yml

@@ -5,6 +5,8 @@ on:
     branches: [master, main]
   pull_request:
     branches: [master, main]
+  schedule:
+    - cron: '31 6 * * 1'
 
 env:
   CARGO_TERM_COLOR: always
@@ -67,28 +69,13 @@ jobs:
       - name: Run Offline Eval Harness
         run: cargo run -p deepseek-tui --all-features -- eval
 
-  build:
-    name: Build
-    runs-on: ${{ matrix.os }}
-    strategy:
-      matrix:
-        os: [ubuntu-latest, macos-latest, windows-latest]
-    steps:
-      - uses: actions/checkout@v4
-      - uses: dtolnay/rust-toolchain@stable
-      - name: Install Linux system dependencies
-        if: runner.os == 'Linux'
-        run: sudo apt-get update && sudo apt-get install -y libdbus-1-dev pkg-config
-      - uses: Swatinem/rust-cache@v2
-      - name: Build
-        run: cargo build --release
-
   npm-wrapper-smoke:
     name: npm wrapper smoke
+    if: github.event_name != 'schedule'
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        os: [ubuntu-latest, macos-latest, windows-latest]
+        os: ${{ fromJSON(github.event_name == 'pull_request' && '["ubuntu-latest"]' || '["ubuntu-latest","macos-latest","windows-latest"]') }}
     steps:
       - uses: actions/checkout@v4
       - uses: dtolnay/rust-toolchain@stable
@@ -107,6 +94,7 @@ jobs:
   # Check documentation builds without warnings
   docs:
     name: Documentation
+    if: github.event_name == 'schedule'
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4