refactor: Restructure monorepo to apps/server/ and apps/web/ layout

Move src/ → apps/server/ and packages/web/ → apps/web/ to adopt
standard monorepo conventions (apps/ for runnable apps, packages/
for reusable libraries). Update all config files, shared package
imports, test fixtures, and documentation to reflect new paths.

Key fixes:
- Update workspace config to ["apps/*", "packages/*"]
- Update tsconfig.json rootDir/include for apps/server/
- Add apps/web/** to vitest exclude list
- Update drizzle.config.ts schema path
- Fix ensure-schema.ts migration path detection (3 levels up in dev,
  2 levels up in dist)
- Fix tests/integration/cli-server.test.ts import paths
- Update packages/shared imports to apps/server/ paths
- Update all docs/ files with new paths

apps/server/trpc/routers/subscription.ts

@@ -0,0 +1,45 @@
+/**
+ * Subscription Router — SSE event streams
+ */
+
+import { z } from 'zod';
+import type { ProcedureBuilder } from '../trpc.js';
+import {
+  eventBusIterable,
+  ALL_EVENT_TYPES,
+  AGENT_EVENT_TYPES,
+  TASK_EVENT_TYPES,
+  PAGE_EVENT_TYPES,
+} from '../subscriptions.js';
+
+export function subscriptionProcedures(publicProcedure: ProcedureBuilder) {
+  return {
+    onEvent: publicProcedure
+      .input(z.object({ lastEventId: z.string().nullish() }).optional())
+      .subscription(async function* (opts) {
+        const signal = opts.signal ?? new AbortController().signal;
+        yield* eventBusIterable(opts.ctx.eventBus, ALL_EVENT_TYPES, signal);
+      }),
+
+    onAgentUpdate: publicProcedure
+      .input(z.object({ lastEventId: z.string().nullish() }).optional())
+      .subscription(async function* (opts) {
+        const signal = opts.signal ?? new AbortController().signal;
+        yield* eventBusIterable(opts.ctx.eventBus, AGENT_EVENT_TYPES, signal);
+      }),
+
+    onTaskUpdate: publicProcedure
+      .input(z.object({ lastEventId: z.string().nullish() }).optional())
+      .subscription(async function* (opts) {
+        const signal = opts.signal ?? new AbortController().signal;
+        yield* eventBusIterable(opts.ctx.eventBus, TASK_EVENT_TYPES, signal);
+      }),
+
+    onPageUpdate: publicProcedure
+      .input(z.object({ lastEventId: z.string().nullish() }).optional())
+      .subscription(async function* (opts) {
+        const signal = opts.signal ?? new AbortController().signal;
+        yield* eventBusIterable(opts.ctx.eventBus, PAGE_EVENT_TYPES, signal);
+      }),
+  };
+}