docs: update CLAUDE.md for the attachments subsystem growth

Document the three PRs that grew attachments since the last update:
COD-37/#119 (registry + magic links) was already covered, but
COD-38/#120 (document previews/thumbnails) and COD-39/#121 (history
drawer) added four source files and several endpoints that weren't
documented. Split a dedicated Attachments row out of Infra, extend the
Attachments Key Pattern to cover the converter pipeline + concurrency
limiter + history drawer, and refresh the files-route handler count
(8 -> 14) and total (~140 -> ~146). Also carries the prior pending
app.js line-count (3.7K -> 3.9K) and config-file-count (10 -> 12) bumps.

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

CLAUDE.md

@@ -127,17 +127,18 @@ Codeman is a Claude Code session manager with web interface and autonomous Ralph
 | **AI** | `src/ai-checker-base.ts`, `src/ai-idle-checker.ts`, `src/ai-plan-checker.ts` | |
 | **Tasks** | `src/task.ts`, `src/task-queue.ts`, `src/task-tracker.ts` | |
 | **State** | `src/state-store.ts`, `src/run-summary.ts`, `src/session-lifecycle-log.ts` | |
-| **Infra** | `src/hooks-config.ts`, `src/push-store.ts`, `src/tunnel-manager.ts`, `src/image-watcher.ts`, `src/file-stream-manager.ts`, `src/attachment-registry.ts`, `src/attachment-magic.ts` | Attachments: see Key Patterns |
+| **Infra** | `src/hooks-config.ts`, `src/push-store.ts`, `src/tunnel-manager.ts`, `src/image-watcher.ts`, `src/file-stream-manager.ts` | |
+| **Attachments** | `src/attachment-registry.ts`, `src/attachment-magic.ts`, `src/session-attachment-history.ts`, `src/document-preview-cache.ts`, `src/document-thumbnailer.ts`, `src/document-conversion-limiter.ts`, `src/config/attachment-guard.ts` | See Key Patterns |
 | **Plan** | `src/plan-orchestrator.ts`, `src/prompts/*.ts`, `src/templates/` (`claude-md.ts` + `case-template.md`, the CLAUDE.md scaffold generated into new cases) | |
 | **Web** | `src/web/server.ts` ★, `src/web/sse-events.ts`, `src/web/routes/*.ts` (16 route modules + barrel; `session-routes.ts` ★), `src/web/route-helpers.ts`, `src/web/ports/*.ts`, `src/web/middleware/auth.ts`, `src/web/schemas.ts`, `src/web/self-update.ts`, `src/web/plan-usage-latest.ts` | |
-| **Frontend** | `src/web/public/app.js` (~3.7K lines, core) + 5 infra modules (`constants.js`, `mobile-handlers.js`, `voice-input.js`, `notification-manager.js`, `keyboard-accessory.js`) + 7 domain modules (`terminal-ui.js`, `respawn-ui.js`, `ralph-panel.js`, `orchestrator-panel.js`, `settings-ui.js`, `panels-ui.js`, `session-ui.js`) + 5 feature modules (`ralph-wizard.js`, `api-client.js`, `subagent-windows.js`, `input-cjk.js`, `image-input.js`) + `sw.js` | |
+| **Frontend** | `src/web/public/app.js` (~3.9K lines, core) + 5 infra modules (`constants.js`, `mobile-handlers.js`, `voice-input.js`, `notification-manager.js`, `keyboard-accessory.js`) + 7 domain modules (`terminal-ui.js`, `respawn-ui.js`, `ralph-panel.js`, `orchestrator-panel.js`, `settings-ui.js`, `panels-ui.js`, `session-ui.js`) + 5 feature modules (`ralph-wizard.js`, `api-client.js`, `subagent-windows.js`, `input-cjk.js`, `image-input.js`) + `sw.js` | |
 | **Types** | `src/types/index.ts` (barrel) → 15 domain files; also `src/types.ts` root re-export | See `@fileoverview` in index.ts |
 
 ★ = Large, central file (>50KB) — read its `@fileoverview` first. All files have `@fileoverview` JSDoc — read that before diving in. Discovery aid: `grep -l '@fileoverview' src/web/routes/*.ts` lists all route modules; same grep works for `src/types/`, `src/web/public/*.js`.
 
 **Local packages**: `packages/xterm-zerolag-input/` — local echo overlay for xterm.js; single-source, bundled to the gitignored `vendor/xterm-zerolag-input.js` and consumed by `app.js` (see Gotchas). `packages/gesture-control/` (`codeman-gesture-control`) — hand-tracking overlay source; built to `src/web/public/gesture/gesture-codeman.js` via `npm run build:gesture` (see Frontend → Gesture control).
 
-**Config**: `src/config/` — 10 files, no barrel (`index.ts`) exists; import from the specific file.
+**Config**: `src/config/` — 12 files, no barrel (`index.ts`) exists; import from the specific file.
 
 **Utilities**: `src/utils/` — re-exported via index. Key: `CleanupManager`, `LRUMap`, `StaleExpirationMap`, `BufferAccumulator`, `stripAnsi`, `Debouncer`, `KeyedDebouncer`. Also: `claude-cli-resolver`/`opencode-cli-resolver`/`codex-cli-resolver` (CLI path resolution), `string-similarity` (fuzzy matching), `regex-patterns` (ANSI/token/spinner patterns), `assertNever` (exhaustive checks), `token-validation` (auth tokens), `nice-wrapper` (process priority).
 
@@ -170,7 +171,7 @@ Codeman is a Claude Code session manager with web interface and autonomous Ralph
 
 **Self-update** (App Settings → Updates): in-app updater for **git-clone installs** supervised by systemd/launchd. Supervisors: `systemd` (user unit), `launchd` (GUI LaunchAgent, gui-domain kickstart), `launchd-daemon` (KeepAlive system LaunchDaemon on headless Macs — restarts rootlessly by killing the server PID and letting launchd respawn it; detected only when the daemon is bootstrapped AND KeepAlive), else `none` → "restart manually" message; on next boot a manual-restart status auto-completes when the running version matches the target. The update restarts the very process running it, so the real work runs in a DETACHED `scripts/self-update.sh` (`git checkout <release tag> && npm install && npm run build && restart`) that outlives the restart; it writes progress to `dataPath('update-status.json')`, which the browser polls across the connection drop. Channel = latest `codeman@X.Y.Z` release tag; dirty trees are auto-stashed. `src/web/self-update.ts` splits PURE helpers (semver/tag parsing, reconcile decision — unit-tested) from IO wrappers (`getInstallInfo`/`checkForUpdate`/`startUpdate`/`reconcileUpdateOnBoot`). Routes: `GET /api/system/update/check`, `POST /api/system/update`, `GET /api/system/update/status`. Types: `src/types/update.ts`. npm installs report as non-updatable.
 
-**Attachments** (live external document references, COD-37/PR #119): two pieces. `attachment-registry.ts` is an **in-memory** registry mapping a stable `attachmentId` → an absolute, `realpath`-resolved, extension-allowlisted file path, so browser requests (`GET /api/sessions/:id/attachments/:attachmentId/raw`) never carry arbitrary absolute paths; `POST /api/sessions/:id/attachments` registers one (both in `file-routes.ts`). `attachment-magic.ts` parses `codeman://attach?...` **magic links** out of terminal output — ⚠️ this scanner is prompt-injectable, so the scan path is **force-confined to the session workspace** (a hostile prompt could otherwise make it read arbitrary host files over SSE). Security gate is an extension **allowlist** (`isSupportedAttachmentExtension`), not a blocklist. Session-local files keep using the existing workspace-scoped `file-routes` paths; the registry is only for explicit live externals.
+**Attachments** (live external document references; COD-37/#119 core, COD-38/#120 previews, COD-39/#121 history): all wiring in `file-routes.ts`. **Registry** (`attachment-registry.ts`): an **in-memory** map of a stable `attachmentId` → an absolute, `realpath`-resolved, extension-allowlisted file path, so browser requests (`GET /api/sessions/:id/attachments/:attachmentId/raw`) never carry arbitrary absolute paths; `POST /api/sessions/:id/attachments` registers one. **Magic links** (`attachment-magic.ts`): parses `codeman://attach?...` out of terminal output — ⚠️ this scanner is prompt-injectable, so the scan path is **force-confined to the session workspace** (a hostile prompt could otherwise make it read arbitrary host files over SSE); emits the `attachment:detected` SSE event. Security gate is an extension **allowlist** (`isSupportedAttachmentExtension`, in the registry/magic modules), not a blocklist; a separate path layer (`config/attachment-guard.ts`) confines reads to the workspace (`attachmentConfineToWorkspace`) and blocks sensitive trees (`/root`, `/etc`). **Previews + thumbnails** (COD-38): `:attachmentId/preview` + `:attachmentId/thumbnail` (and the workspace-file equivalents `file-preview`/`file-thumbnail`) render Office docs/PDFs via external converters (`pdftoppm` / LibreOffice `soffice` / Word-COM `powershell`); `document-preview-cache.ts` is a shared disk cache (de-dups *identical* in-flight inputs), `document-thumbnailer.ts` does best-effort first-page images, and `document-conversion-limiter.ts` is a **global converter-spawn concurrency cap** (`runWithConversionLimit`) — without it, N distinct large docs detected at once fork N multi-minute converter processes = a localhost fork-bomb-shaped resource-exhaustion vector. **History drawer** (COD-39): `session-attachment-history.ts` tracks the last `ATTACHMENT_HISTORY_LIMIT` (100) attachments per session (`Session._attachmentHistory`, persisted via `SessionState.attachmentHistory`, replayed so externals re-register on reconnect); `GET /api/sessions/:id/attachments` is the list endpoint. ⚠️ The history drawer's launcher button is desktop-only — hidden on phones (regression-guarded; see `mobile-header-buttons-policy` test). Session-local files keep using the existing workspace-scoped `file-routes` paths; the registry is only for explicit live externals.
 
 **Port interfaces**: Routes declare dependencies via port interfaces (`src/web/ports/`). Routes use intersection types (e.g., `SessionPort & EventPort`).
 
@@ -218,7 +219,7 @@ Frontend JS modules have `@fileoverview` with `@dependency`/`@loadorder` tags. L
 
 ### API Routes
 
-~140 handlers across 16 route files in `src/web/routes/`: system (41, incl. self-update `check`/`status`/`POST /api/system/update`, `POST /api/system/span-displays` → spawns `scripts/span-codeman.sh`, and `GET /api/codex/status`), sessions (29), orchestrator (10), cases (9), ralph (9), plan (8), files (8, incl. attachment register + `:attachmentId/raw`), respawn (7), mux (5), push (4), scheduled (4), teams (2), hooks (1), clipboard (1), status-telemetry (1, `POST /api/status-telemetry` ← statusLine exporter), ws (1 WebSocket). Each file has `@fileoverview` with endpoint details.
+~146 handlers across 16 route files in `src/web/routes/`: system (41, incl. self-update `check`/`status`/`POST /api/system/update`, `POST /api/system/span-displays` → spawns `scripts/span-codeman.sh`, and `GET /api/codex/status`), sessions (29), orchestrator (10), cases (9), ralph (9), plan (8), files (14, incl. attachment register + list/history + `:attachmentId/raw`/`preview`/`thumbnail` + workspace `file-preview`/`file-thumbnail`), respawn (7), mux (5), push (4), scheduled (4), teams (2), hooks (1), clipboard (1), status-telemetry (1, `POST /api/status-telemetry` ← statusLine exporter), ws (1 WebSocket). Each file has `@fileoverview` with endpoint details.
 
 **HTTP contract** (stable since 0.9.x, see `docs/versioning-policy.md`; full envelope/status/error-code/SSE spec in `docs/api-reference.md`): responses use the `ApiResponse<T>` envelope — `{ success: true, data? }` or `{ success: false, error, errorCode }` (`src/types/api.ts`). `/api/v1/*` is a versioned alias of `/api/*` (URL rewrite in `server.ts`).