refactor: codebase audit cleanup — dead code, dedup, module splits

Multi-agent audit + aggressive cleanup across server/web/coder/booterm,
delivered behind a DEFER discipline so none of the in-flight files were
touched. Removes dead code/deps/columns, dedups server + coder helpers,
and splits the oversized modules (tools.ts, opencode-server.ts,
sentinel-summaries, turn.ts, TerminalPane.tsx) behind stable contracts.
Adds 78 parity/unit tests (server 587, coder 323); fixes two latent bugs
(ChatPane queue keys, FileViewerOverlay blank-line parity).

Intended tag: v2.7.12-audit-cleanup.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

CHANGELOG.md

@@ -2,6 +2,10 @@
 
 All notable changes per release tag. Most recent on top, ordered by tag creation date (which matches the git history). Tag names follow `vMAJOR.MINOR.PATCH-slug` — the slug describes what shipped, so the tag name alone is enough to recall the batch.
 
+## v2.7.12-audit-cleanup — 2026-06-02
+
+A repo-wide audit and aggressive cleanup pass, run as a multi-agent orchestration (five read-only Opus auditors over server/web/coder/booterm + cross-cutting deps/build/parity + a structural-architecture lens) followed by phased, behavior-preserving implementation — every change gated on the per-app test suites and delivered behind a strict DEFER discipline that never touched the files in flight for `v2.7.9`–`v2.7.11` (`mcp-config`, the `ws-frames` pair, `dispatcher`, `claude-sdk-map`, `AgentComposerBar`/`CoderMessageList`/`CoderPane`), so the branch rebased onto current main with zero conflicts. **Dead code/deps/schema**: removed ~9 dead files and a swathe of dead exports/write-only state across all four apps, dropped dead deps (`next-themes`, `@xterm/addon-webgl`, booterm `tslib`; `shadcn`→devDep), and idempotently dropped dead schema columns/tables (`sessions.tags`, `tasks.worktree_path`/`feature_values`, `available_agents.supports_mcp_client`, the superseded `session_worktrees` table, the always-empty `list_worktrees` MCP tool) — chat/session/message DATA untouched, only never-read columns. **Server dedup + reshapes**: collapsed the dead `budget.ts` tier system (surfacing a latent `READ_ONLY_TOOL_NAMES` drift, then deleted), extracted shared `MESSAGE_COLUMNS`/`selectProject`/`stripQuotes`/`SENTINEL_KINDS`/`samplerOptsFromAgent`/`createContentFlusher`/`insertSentinel`/a `makeCodecontextTool` factory/a pending-tool-call resolver, split `tools.ts` (799→46 barrel + `tools/{types,fs-tools,misc-tools,registry,tiers}`, register-through registry preserved so coder's import contract stays byte-stable), and decomposed the inference pipeline (`sentinel-summaries`→`runWrapUpSummary`, `turn.ts`→`turn-config`+`step-decision`, a pure `stream-phase-adapter`, shared finalize atoms — stopping short of fusing synthesis to preserve frame timing). **Coder reshapes**: split the 1062-line `opencode-server.ts` god-class into supervisor / sse-loop / pure event-map / port-utils + extracted `buildAcpClient`/`makeFrameEmitter`/`worktree-risk`, plus happy-path-safe concurrency hardening (reconnect backoff, double-spawn guard; a defensive busy-assert + ensureSession coalescing flagged for review). **Web**: `React.memo` on `MessageBubble`/`MarkdownRenderer` + module-hoisted markdown components (the streaming re-parse was the biggest perf cost), shared `linkifyPaths`/artifact/tab dedup, two latent bug fixes (`ChatPane` index-keys → stable ids; `FileViewerOverlay` blank-line line-number desync), and decomposed the 1298-line `TerminalPane.tsx` into fit/socket/selection hooks + presentational pieces (verbatim move, all ~30 listeners/timers inventoried; the label-dep fix stops a live terminal tearing down on pane renumber). +78 parity/unit tests (server 597, coder 328 green; `apps/web` has no harness, so its changes are typecheck + manual/device QA). Net ≈ −4,600 LOC. Deferred (designed; blueprints in the audit reports): the `tasks` dual-CREATE / `project_id` FK (a cross-service deploy-ordering decision, not a data migration), web structural decomposition of `useWorkspacePanes`/`MessageBubble` (needs a web test harness first), a `@boocode/contracts` shared package, and the `dispatcher.ts` split — the last two now unblocked since their in-flight files shipped in `v2.7.9`–`v2.7.11`. Rebased clean onto `v2.7.11-coder-model-snapshot`.
+
 ## v2.7.11-coder-model-snapshot — 2026-06-02
 
 Hotfix for the coder model-attribution chip vanishing on refresh. The chip showed during a live turn (the `message_complete` frame carries `model`) but disappeared when a BooCoder session was reloaded — only in the coder, not BooChat. Root cause: `CoderPane`'s `useCoderMessages` hydrates from two sources on load — the HTTP `listMessages` fetch (whose SELECT includes `model`, added `v2.7.8`) AND the WS `snapshot` frame — and the WS snapshot's query in `apps/coder/src/routes/ws.ts` had its own column list that omitted `model`. The client's `snapshot` handler `setMessages`-overwrites the HTTP load, so the model-less rows won, and with no later `message_complete` for historical messages the chip stayed gone. Fix is one column: add `model` to the WS snapshot SELECT so both hydration paths agree. The `apps/coder/CLAUDE.md` "update every mapper" note now lists the WS snapshot SELECT explicitly (it was the one place not enumerated). apps/server + apps/coder builds green; deployed via `systemctl restart boocoder` (host service — the earlier `v2.7.10` docker deploy rebuilt only the container, never this route). Fixes the chip shipped in `v2.7.8-ember-coder-tabs-model-chips` / completed in `v2.7.9-mcp-keys-docs-coder-fixes`.