[codex] harden authenticated routes and issue editor reliability (#3741)

## Thinking Path

> - Paperclip orchestrates AI agents for zero-human companies
> - The control plane depends on authenticated routes enforcing company
boundaries and role permissions correctly
> - This branch also touches the issue detail and markdown editing flows
operators use while handling advisory and triage work
> - Partial issue cache seeds and fragile rich-editor parsing could
leave important issue content missing or blank at the moment an operator
needed it
> - Blocked issues becoming actionable again should wake their assignee
automatically instead of silently staying idle
> - This pull request rebases the advisory follow-up branch onto current
`master`, hardens authenticated route authorization, and carries the
issue-detail/editor reliability fixes forward with regression tests
> - The benefit is tighter authz on sensitive routes plus more reliable
issue/advisory editing and wakeup behavior on top of the latest base

## What Changed

- Hardened authenticated route authorization across agent, activity,
approval, access, project, plugin, health, execution-workspace,
portability, and related server paths, with new cross-tenant and
runtime-authz regression coverage.
- Switched issue detail queries from `initialData` to placeholder-based
hydration so list/quicklook seeds still refetch full issue bodies.
- Normalized advisory-style HTML images before mounting the markdown
editor and strengthened fallback behavior when the rich editor silently
fails or rejects the content.
- Woke assigned agents when blocked issues move back to `todo`, with
route coverage for reopen and unblock transitions.
- Rebasing note: this branch now sits cleanly on top of the latest
`master` tip used for the PR base.

## Verification

- `pnpm exec vitest run ui/src/lib/issueDetailQuery.test.tsx
ui/src/components/MarkdownEditor.test.tsx
server/src/__tests__/issue-comment-reopen-routes.test.ts
server/src/__tests__/activity-routes.test.ts
server/src/__tests__/agent-cross-tenant-authz-routes.test.ts`
- Confirmed `pnpm-lock.yaml` is not part of the PR diff.
- Rebased the branch onto current `public-gh/master` before publishing.

## Risks

- Broad authz tightening may expose existing flows that were relying on
permissive board or agent access and now need explicit grants.
- Markdown editor fallback changes could affect focus or rendering in
edge-case content that mixes HTML-like advisory markup with normal
markdown.
- This verification was intentionally scoped to touched regressions and
did not run the full repository suite.

## Model Used

- OpenAI Codex, GPT-5-based coding agent in the Codex CLI environment
with tool use for terminal, git, and GitHub operations. The exact
runtime model identifier is not exposed inside this session.

## Checklist

- [x] I have included a thinking path that traces from project context
to this change
- [x] I have specified the model used (with version and capability
details)
- [x] I have run tests locally and they pass
- [x] I have added or updated tests where applicable
- [x] If this change affects the UI, it is behavior-only and does not
need before/after screenshots
- [x] I have updated relevant documentation to reflect my changes, or no
documentation changes were needed for these internal fixes
- [x] I have considered and documented any risks above
- [x] I will address all Greptile and reviewer comments before
requesting merge

---------

Co-authored-by: Paperclip <noreply@paperclip.ing>

server/src/__tests__/activity-routes.test.ts

@@ -28,7 +28,15 @@ vi.mock("../services/index.js", () => ({
   heartbeatService: () => mockHeartbeatService,
 }));
 
-async function createApp() {
+async function createApp(
+  actor: Record<string, unknown> = {
+    type: "board",
+    userId: "user-1",
+    companyIds: ["company-1"],
+    source: "session",
+    isInstanceAdmin: false,
+  },
+) {
   const [{ errorHandler }, { activityRoutes }] = await Promise.all([
     import("../middleware/index.js"),
     import("../routes/activity.js"),
@@ -36,13 +44,7 @@ async function createApp() {
   const app = express();
   app.use(express.json());
   app.use((req, _res, next) => {
-    (req as any).actor = {
-      type: "board",
-      userId: "user-1",
-      companyIds: ["company-1"],
-      source: "session",
-      isInstanceAdmin: false,
-    };
+    (req as any).actor = actor;
     next();
   });
   app.use("/api", activityRoutes({} as any));
@@ -105,4 +107,13 @@ describe("activity routes", () => {
     expect(res.status).toBe(403);
     expect(mockActivityService.issuesForRun).not.toHaveBeenCalled();
   });
+
+  it("rejects anonymous heartbeat run issue lookups before run existence checks", async () => {
+    const app = await createApp({ type: "none", source: "none" });
+    const res = await request(app).get("/api/heartbeat-runs/missing-run/issues");
+
+    expect(res.status).toBe(401);
+    expect(mockHeartbeatService.getRun).not.toHaveBeenCalled();
+    expect(mockActivityService.issuesForRun).not.toHaveBeenCalled();
+  });
 });