fix(api): close contract gaps found by post-merge adversarial audit

A 15-agent audit of the merged tree confirmed 9 envelope/contract bugs;
all fixed here, with live-server contract tests added:

Blockers (fresh-install quick start broken):
- session-ui.js runClaude/runShell unwrapped .data from the /api/cases/:name
  404 error envelope (which has no data key), so a not-yet-created case threw
  TypeError instead of triggering the auto-create fallback. Now '?.data ?? {}'.

Contract violations on the new stable surface:
- Unknown /api routes returned HTTP 404 with {success:true,...} (Fastify's
  default not-found payload was wrapped by the envelope hook). Added a
  setNotFoundHandler returning the standard error envelope for /api paths.
- POST /api/events/subscribe 400 body became {success:true,data:{error}};
  now createErrorResponse(INVALID_INPUT).
- POST /api/clipboard validation error lacked errorCode and shipped HTTP 200;
  now createErrorResponse(INVALID_INPUT) -> 400.
- POST /api/run catch path returned bare {success:false,sessionId,error}
  (HTTP 200, no errorCode); now OPERATION_FAILED envelope -> 422 with the
  dead session id in the message.
- DELETE tail-file/:streamId returned {success: closed}, colliding with the
  envelope discriminator; now returns {closed}.

Dead/regressed UI paths:
- Plan history modal could never open: route returned the bare history array
  under data while the frontend read data.data.history/currentVersion. Route
  now returns {history, currentVersion}; modal task count fixed to stats.total.
- Self-update error toast read j.error.message from the string-typed envelope
  error, always falling back to the generic message; now reads the string.

Cleanup:
- Removed the stale QuickStartResponse type (unreferenced; documented the
  pre-envelope shape and invited success-key collisions).

Tests: new test/http-contract.test.ts boots a real WebServer (port 3168) and
pins the envelope, /api/v1 alias, error statuses, and the /api 404 shape —
the route-test harness does not install the server-level hook, so these need
the live server. Updated file-routes/plan-routes/scheduled-runs tests to the
fixed shapes.

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

src/web/routes/clipboard-routes.ts

@@ -6,13 +6,14 @@
 import { FastifyInstance } from 'fastify';
 import { SseEvent } from '../sse-events.js';
 import type { EventPort } from '../ports/index.js';
+import { createErrorResponse, ApiErrorCode } from '../../types.js';
 
 export function registerClipboardRoutes(app: FastifyInstance, ctx: EventPort): void {
   app.post('/api/clipboard', async (req) => {
     const body = req.body as { text?: string; sessionId?: string };
     const text = body?.text;
     if (typeof text !== 'string' || text.length === 0) {
-      return { success: false, error: 'Missing or empty "text" field' };
+      return createErrorResponse(ApiErrorCode.INVALID_INPUT, 'Missing or empty "text" field');
     }
     ctx.broadcast(SseEvent.ClipboardWrite, {
       text,

src/web/routes/file-routes.ts

@@ -375,12 +375,15 @@ export function registerFileRoutes(app: FastifyInstance, ctx: SessionPort): void
     });
   });
 
-  // Close a file stream
+  // Close a file stream. Returns { closed } rather than { success: closed } —
+  // a top-level `success` key would collide with the envelope discriminator
+  // (the preSerialization hook would pass `{success:false}` through as a
+  // malformed error envelope instead of wrapping it).
   app.delete('/api/sessions/:id/tail-file/:streamId', async (req) => {
     const { id, streamId } = req.params as { id: string; streamId: string };
     findSessionOrFail(ctx, id); // Validates session exists
     const closed = fileStreamManager.closeStream(streamId);
-    return { success: closed };
+    return { closed };
   });
   // Session-scoped file download.
   // Uses the same realpath-based workspace boundary as file preview/raw routes;

src/web/routes/plan-routes.ts

@@ -408,7 +408,7 @@ NOW: Generate the implementation plan for the task above. Think step by step.`;
       return createErrorResponse(ApiErrorCode.OPERATION_FAILED, 'Ralph tracker not available');
     }
 
-    return { success: true, data: tracker.getPlanHistory() };
+    return { success: true, data: { history: tracker.getPlanHistory(), currentVersion: tracker.planVersion } };
   });
 
   // ========== Rollback to Version ==========

src/web/routes/session-routes.ts

@@ -1086,9 +1086,10 @@ export function registerSessionRoutes(
       await ctx.cleanupSession(session.id, true, 'run_prompt_complete');
       return { sessionId: session.id, ...result };
     } catch (err) {
-      // Clean up session on error too
+      // Clean up session on error too. The session is destroyed here, so its id
+      // is only useful for log correlation — carry it in the error message.
       await ctx.cleanupSession(session.id, true, 'run_prompt_error');
-      return { success: false, sessionId: session.id, error: getErrorMessage(err) };
+      return createErrorResponse(ApiErrorCode.OPERATION_FAILED, `${getErrorMessage(err)} (session ${session.id})`);
     }
   });