feat(usage): plan usage limits header chip via statusLine telemetry

Surface Claude subscription plan usage limits (5-hour rolling + 7-day
weekly: percent used + reset time) in the header, opt-in via App Settings
→ Display → "Plan Usage Limits" (default OFF, no behavior change when off).

A Codeman-managed Claude statusLine exporter forwards the rate_limits JSON
to a new auth-exempt POST /api/status-telemetry (same loopback + hook-secret
gate as /api/hook-event); parsed telemetry broadcasts over SSE
session:statusTelemetry to a header chip (amber >=80%, red >=95%, reset
times on hover). The exporter prints the same summary back as the
in-terminal footer (print-through).

- src/usage-telemetry.ts: pure parser/formatter (epoch-sec -> ms, clamp,
  change signature) + test/usage-telemetry.test.ts
- hooks-config.ts: generateStatusLineCommand + applyStatusLineConfig
  (add/remove; never clobbers a user's own statusLine)
- session-routes.ts: inject gate (Claude-only, Codeman-managed cases),
  driven by create-payload statusLineTelemetry (session-ui.js)
- schemas.ts: StatusTelemetrySchema + showPlanUsageLimits + payload field
- frontend: header chip, applyHeaderVisibilitySettings toggle,
  renderIndexHtml strip, _onSessionStatusTelemetry handler

Schema empirically confirmed against Claude Code 2.1.177 (Claude Max):
only five_hour/seven_day windows exist (no Opus-weekly field); rate_limits
is absent before the first API response and for non-subscriber auth. Design
+ verification method in docs/usage-limits-display-plan.md.

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

src/web/routes/index.ts

@@ -9,6 +9,7 @@ export { registerFileRoutes } from './file-routes.js';
 export { registerScheduledRoutes } from './scheduled-routes.js';
 export { registerSystemRoutes } from './system-routes.js';
 export { registerHookEventRoutes } from './hook-event-routes.js';
+export { registerStatusTelemetryRoutes } from './status-telemetry-routes.js';
 export { registerCaseRoutes } from './case-routes.js';
 export { registerSessionRoutes } from './session-routes.js';
 export { registerRespawnRoutes } from './respawn-routes.js';

src/web/routes/session-routes.ts

@@ -45,7 +45,7 @@ import {
   validatePathWithinBase,
 } from '../route-helpers.js';
 import { AUTH_COOKIE_NAME } from '../middleware/auth.js';
-import { writeHooksConfig, updateCaseModel, stripCaseEnvKeys } from '../../hooks-config.js';
+import { writeHooksConfig, updateCaseModel, stripCaseEnvKeys, applyStatusLineConfig } from '../../hooks-config.js';
 import { generateClaudeMd } from '../../templates/claude-md.js';
 import { imageWatcher } from '../../image-watcher.js';
 import { getLifecycleLog } from '../../session-lifecycle-log.js';
@@ -297,6 +297,14 @@ export function registerSessionRoutes(
       await updateCaseModel(workingDir, body.modelOverride || null);
     }
 
+    // Plan-usage statusLine exporter (App Settings → Display → "Plan Usage
+    // Limits"). Claude-only, and only inside Codeman-managed cases (never
+    // arbitrary user repos, which may carry a hand-authored statusLine). Adds or
+    // removes our exporter so toggling the setting off cleans up on next create.
+    if ((body.mode ?? 'claude') === 'claude' && workingDir.startsWith(CASES_DIR + '/')) {
+      await applyStatusLineConfig(workingDir, body.statusLineTelemetry === true);
+    }
+
     // Check OpenCode availability if requested
     if (body.mode === 'opencode') {
       const { isOpenCodeAvailable } = await import('../../utils/opencode-cli-resolver.js');

src/web/routes/status-telemetry-routes.ts

@@ -0,0 +1,63 @@
+/**
+ * @fileoverview Status-telemetry route.
+ *
+ * Receives Claude Code statusline payloads POSTed by the Codeman-managed
+ * statusLine exporter (see `hooks-config.generateStatusLineCommand`) and
+ * broadcasts the parsed plan-usage limits (5-hour + weekly) to SSE clients for
+ * the header "Plan Usage Limits" chip. Auth-exempt like `/api/hook-event`
+ * (localhost-only; hook-secret-gated while a tunnel runs — see middleware/auth).
+ *
+ * Returns a compact plain-text status string for the exporter to print as the
+ * in-terminal footer (print-through), so injecting our statusLine doesn't leave
+ * the terminal footer blank.
+ */
+
+import { FastifyInstance } from 'fastify';
+import { StatusTelemetrySchema } from '../schemas.js';
+import { parseBody } from '../route-helpers.js';
+import {
+  parseStatusTelemetry,
+  formatStatusLineText,
+  telemetrySignature,
+  type RawStatuslinePayload,
+} from '../../usage-telemetry.js';
+import { SessionStatusTelemetry } from '../sse-events.js';
+import type { SessionPort, EventPort } from '../ports/index.js';
+
+export function registerStatusTelemetryRoutes(app: FastifyInstance, ctx: SessionPort & EventPort): void {
+  // Last broadcast telemetry signature per session — the statusline fires on
+  // every assistant message, so we only rebroadcast when the value changes.
+  const lastSig = new Map<string, string>();
+
+  app.post('/api/status-telemetry', async (req, reply) => {
+    const { sessionId, data } = parseBody(StatusTelemetrySchema, req.body);
+
+    reply.type('text/plain; charset=utf-8');
+
+    // Unknown session — minimal footer, no broadcast.
+    if (!ctx.sessions.has(sessionId)) {
+      lastSig.delete(sessionId);
+      return 'codeman';
+    }
+
+    const telemetry = parseStatusTelemetry(data as RawStatuslinePayload | undefined);
+    if (!telemetry) {
+      // No plan-limit data yet (pre-first-response or non-subscriber auth).
+      return 'codeman';
+    }
+
+    const sig = telemetrySignature(telemetry);
+    if (lastSig.get(sessionId) !== sig) {
+      lastSig.set(sessionId, sig);
+      // Bound the map across long multi-session runs: prune dead sessions.
+      if (lastSig.size > 256) {
+        for (const id of [...lastSig.keys()]) {
+          if (!ctx.sessions.has(id)) lastSig.delete(id);
+        }
+      }
+      ctx.broadcast(SessionStatusTelemetry, { sessionId, ...telemetry });
+    }
+
+    return formatStatusLineText(telemetry);
+  });
+}