[codex] Move instance settings under company settings (#7680)

## Thinking Path

> - Paperclip is the open source app people use to manage AI agents for
work
> - Operators manage both company-scoped configuration and
instance-level runtime/admin settings from the board UI
> - Instance settings previously lived as their own top-level sidebar
area, separate from the company settings context operators already use
> - That split made settings navigation feel heavier and made instance
configuration less discoverable from the settings tab
> - This pull request moves instance settings under company settings
while preserving the existing instance settings routes and plugin/admin
surfaces
> - The benefit is a smaller primary sidebar and a more coherent
settings hierarchy for operators

## Linked Issues or Issue Description

- Refs #338
- Internal: PAP-10491, PAP-10538

## What Changed

- Moved instance settings navigation under the company settings area.
- Added route helpers and sidebar entries for nested instance settings
paths.
- Updated plugin/admin settings routes to use the company settings
instance scope.
- Preserved legacy instance-settings bookmarks through compatibility
redirects that keep the active company prefix.
- Updated focused UI and plugin tests for the new navigation shape.
- Stabilized the process-loss retry test that was failing the serialized
server shard in CI.
- Rebased the branch onto current `paperclipai/paperclip` `master` and
pushed the current head.

## Verification

- `pnpm exec vitest run
ui/src/components/CompanySettingsSidebar.test.tsx
ui/src/components/access/CompanySettingsNav.test.tsx
ui/src/lib/instance-settings.test.ts
ui/src/components/InstanceSidebar.test.tsx
ui/src/components/Layout.test.tsx
ui/src/components/SidebarAccountMenu.test.tsx
ui/src/pages/PluginPage.test.tsx ui/src/plugins/bridge.test.ts
packages/shared/src/validators/plugin.test.ts`
- `pnpm exec vitest run ui/src/lib/instance-settings.test.ts
ui/src/components/CompanySettingsSidebar.test.tsx
ui/src/components/access/CompanySettingsNav.test.tsx
ui/src/components/Layout.test.tsx ui/src/plugins/bridge.test.ts`
- `pnpm exec vitest run
server/src/__tests__/heartbeat-process-recovery.test.ts -t "queues
exactly one retry when the recorded local pid is dead"`
- `pnpm test:run:serialized -- --shard-index 0 --shard-count 4`
- GitHub PR checks are green on head
`fe7b0955169dcae55cbe10889c1876a70ab0b80c`, including `verify`, `General
tests (server)`, all serialized server shards, build, e2e, policy,
security checks, and Greptile.
- Confirmed the PR diff does not include `pnpm-lock.yaml` or
`.github/workflows` changes.

## Risks

- Medium UI/navigation risk: instance settings links are intentionally
moving under company settings, so stale external bookmarks to legacy
paths rely on the compatibility routing in this branch.
- Low test-only risk from the CI stabilization commit: it makes the
recovery assertion select the actual retry run by `retryOfRunId` instead
of whichever non-original run appears first.
- No database migrations.
- No dependency lockfile or workflow changes.

> For core feature work, check [`ROADMAP.md`](ROADMAP.md) first and
discuss it in `#dev` before opening the PR. Feature PRs that overlap
with planned core work may need to be redirected — check the roadmap
first. See `CONTRIBUTING.md`.

## Model Used

- OpenAI Codex coding agent based on GPT-5, with shell/tool execution in
a local repository worktree. Exact context window was not exposed by the
runtime.

## 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 checked ROADMAP.md and confirmed this PR does not duplicate
planned core work
- [x] I have searched GitHub for duplicate or related PRs and linked
them above
- [x] I have either (a) linked existing issues with `Fixes: #` / `Closes
#` / `Refs #` OR (b) described the issue in-PR following the relevant
issue template
- [x] I have run tests locally and they pass
- [x] I have added or updated tests where applicable
- [ ] If this change affects the UI, I have included before/after
screenshots
- [x] I have updated relevant documentation to reflect my changes
- [x] I have considered and documented any risks above
- [x] All Paperclip CI gates are green
- [x] Greptile is 5/5 with no open P2s, recommendations, or follow-ups
- [x] I will address all Greptile and reviewer comments before
requesting merge

---------

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

ui/src/components/SidebarAccountMenu.test.tsx

@@ -1,6 +1,5 @@
 // @vitest-environment jsdom
 
-import { act } from "react";
 import { createRoot } from "react-dom/client";
 import { QueryClient, QueryClientProvider } from "@tanstack/react-query";
 import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
@@ -44,6 +43,12 @@ vi.mock("../context/ThemeContext", () => ({
 // eslint-disable-next-line @typescript-eslint/no-explicit-any
 (globalThis as any).IS_REACT_ACT_ENVIRONMENT = true;
 
+async function act(callback: () => void | Promise<void>) {
+  await callback();
+  await Promise.resolve();
+  await new Promise((resolve) => window.setTimeout(resolve, 0));
+}
+
 async function flushReact() {
   await act(async () => {
     await Promise.resolve();
@@ -85,7 +90,6 @@ describe("SidebarAccountMenu", () => {
         <QueryClientProvider client={queryClient}>
           <SidebarAccountMenu
             deploymentMode="authenticated"
-            instanceSettingsTarget="/instance/settings/general"
             version="1.2.3"
           />
         </QueryClientProvider>,
@@ -106,11 +110,13 @@ describe("SidebarAccountMenu", () => {
     await flushReact();
 
     expect(document.body.textContent).toContain("Edit profile");
+    expect(document.body.textContent).not.toContain("Instance settings");
     expect(document.body.textContent).toContain("Documentation");
     expect(document.body.textContent).toContain("Paperclip v1.2.3");
     expect(document.body.textContent).toContain("jane@example.com");
     expect(document.body.querySelector('[data-slot="popover-content"]')?.className)
       .toContain("w-[277px]");
+    expect(document.body.querySelector('a[href="/company/settings/instance/profile"]')).not.toBeNull();
 
     await act(async () => {
       root.unmount();