fix(notepad-guard,start-work): wire dispatch and match .omo paths

notepad-write-guard:
- The hook was created by create-tool-guard-hooks but tool-execute-before
  never invoked it, so the guard was inert.
- It also only matched .sisyphus/notepads, missing the current
  .omo/notepads layout introduced by the workspace migration.
- Add the dispatch call alongside writeExistingFileGuard, and extend
  NOTEPAD_ROOTS to cover both paths via normalize() + sep. New
  integration test pins the wire and the .omo block; the existing unit
  test now asserts both paths.

start-work session-plan-affinity:
- PLAN_PATH_PATTERN only matched .sisyphus/plans, so sessions referring
  to plans under .omo/plans returned null and start-work missed the
  current session's own plan.
- Extend the regex to .(sisyphus|omo)/plans and add findPrometheusPlans
  in packages/boulder-state to scan both directories during the
  transition. New regression test pins .omo/plans matching; legacy
  .sisyphus/plans coverage preserved.

src/hooks/start-work/session-plan-affinity.test.ts

@@ -0,0 +1,40 @@
+/// <reference types="bun-types" />
+
+import { describe, expect, test } from "bun:test"
+import { join } from "node:path"
+import { tmpdir } from "node:os"
+import { findRecentSessionPlanPath } from "./session-plan-affinity"
+import { unsafeTestValue } from "../../../test-support/unsafe-test-value"
+
+type FindRecentSessionPlanPathInput = Parameters<typeof findRecentSessionPlanPath>[0]
+
+describe("findRecentSessionPlanPath", () => {
+  test("#given session history references omo plan path #when finding recent plan #then returns matching plan", async () => {
+    const directory = join(tmpdir(), "session-plan-affinity-test")
+    const planPath = join(directory, ".omo", "plans", "foo-bar.md")
+    const client = unsafeTestValue<FindRecentSessionPlanPathInput["client"]>({
+      session: {
+        messages: async () => ({
+          data: [
+            {
+              parts: [
+                {
+                  text: "Plan saved to .omo/plans/foo-bar.md",
+                },
+              ],
+            },
+          ],
+        }),
+      },
+    })
+
+    const result = await findRecentSessionPlanPath({
+      client,
+      directory,
+      sessionID: "session-123",
+      availablePlans: [planPath],
+    })
+
+    expect(result).toBe(planPath)
+  })
+})

src/hooks/start-work/session-plan-affinity.ts

@@ -3,7 +3,7 @@ import type { PluginInput } from "@opencode-ai/plugin"
 import { normalizeSDKResponse } from "../../shared"
 import { log } from "../../shared/logger"
 
-const PLAN_PATH_PATTERN = /[A-Za-z0-9_./\\:-]*\.sisyphus[\\/]plans[\\/][A-Za-z0-9._/\\-]+\.md/gi
+const PLAN_PATH_PATTERN = /[A-Za-z0-9_./\\:-]*\.(?:sisyphus|omo)[\\/]plans[\\/][A-Za-z0-9._/\\-]+\.md/gi
 
 interface SessionMessagePart {
   text?: string