[codex] Add agent permissions and controls plan (#6386)

## Thinking Path

> - Paperclip orchestrates AI agents for zero-human companies by keeping
task ownership, approvals, and operator control inside one control
plane.
> - Agent permissions and plugin-hosted company settings sit on the
boundary between autonomy and governance.
> - V1 needs scoped task assignment rules, plugin extension points, and
clearer company access surfaces without weakening company boundaries.
> - The branch builds the core authorization service, plugin SDK/host
APIs, and UI simplifications needed to support those controls.
> - Paperclip EE plugin surfaces were intentionally moved out of this
core PR per review direction, so this PR now carries only the public
core/plugin infrastructure work.
> - The latest updates preserve the PAP-9937 branch changes that belong
in this PR, remove the `design/` artifacts, and exclude the experimental
`plugin-briefs` package.
> - Greptile feedback was applied through the authorization/audit paths
and the final cleanup commit was re-reviewed at 5/5 with no unresolved
Greptile threads.
> - The benefit is safer assignment control with extension hooks for
richer permission products while preserving simple defaults for normal
operators.

## What Changed

- Added scoped task-assignment authorization decisions and routed
issue/agent assignment mutations through the authorization service.
- Added plugin SDK and host APIs for company settings slots,
authorization policy/grant management, assignment previews, and bridge
invocation scope propagation.
- Simplified core company access UI and moved advanced controls behind
plugin-provided settings surfaces.
- Added retry-now affordances for blocked issue next-step notices.
- Added protected-assignment enforcement for persisted
agent/project/issue policies, including explicit-grant fallback
behavior.
- Added incremental principal-access compatibility backfill for active
agent memberships and role-default human permission grants.
- Added the Markdown code block wrap action fix from the latest branch
changes.
- Removed `design/` artifacts from the PR and removed
`packages/plugins/plugin-briefs` from the final diff.
- Addressed Greptile feedback for plugin actor sanitization, legacy
membership handling, audit pagination, unknown grant-scope metadata, and
startup test mocks.

## Verification

- `pnpm exec vitest run server/src/__tests__/access-service.test.ts
server/src/__tests__/company-portability.test.ts` -> 2 files passed, 54
tests passed.
- `pnpm exec vitest run
server/src/__tests__/server-startup-feedback-export.test.ts
server/src/__tests__/access-service.test.ts
server/src/__tests__/company-portability.test.ts` -> 3 files passed, 62
tests passed.
- `pnpm exec vitest run
server/src/__tests__/authorization-service.test.ts
server/src/__tests__/plugin-access-authorization-host-services.test.ts
server/src/__tests__/server-startup-feedback-export.test.ts` -> 3 files
passed, 28 tests passed.
- `pnpm --filter @paperclipai/server typecheck` -> passed.
- `git diff --check` -> passed.
- `node ./scripts/check-docker-deps-stage.mjs` -> passed.
- `CI=true pnpm install --frozen-lockfile --ignore-scripts` -> passed
with no lockfile update.
- `pnpm exec vitest run
ui/src/components/MarkdownBody.interaction.test.tsx` -> 1 test passed.
- `git ls-files design packages/plugins/plugin-briefs | wc -l` -> 0.
- GitHub CI on `40cd83b53` -> all checks passed, merge state `CLEAN`.
- Greptile on `40cd83b53` -> 5/5, 102 files reviewed, 0
comments/annotations added, 0 unresolved review threads.
- Confirmed the PR diff contains no `design/`,
`packages/plugins/plugin-briefs`, `pnpm-lock.yaml`, or
`.github/workflows` changes.

## Risks

- Medium: task assignment authorization paths are behaviorally stricter
for protected/private policy data, so existing plugin-authored policies
may block assignment until explicit grants or approval flows are
configured.
- Medium: plugin-host authorization APIs expand the surface area
available to trusted plugins and need careful review for company
scoping.
- Low: startup now performs a principal-access compatibility backfill,
but the migration and runtime backfill use conflict-tolerant inserts.

> 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, GPT-5 coding agent, tool-enabled workflow with shell,
git, and GitHub CLI access.

## 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 run tests locally and they pass
- [x] I have added or updated tests where applicable
- [x] 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] I will address all Greptile and reviewer comments before
requesting merge

---------

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

server/src/__tests__/issue-agent-mutation-ownership-routes.test.ts

@@ -30,6 +30,7 @@ const mockIssueService = vi.hoisted(() => ({
 
 const mockAccessService = vi.hoisted(() => ({
   canUser: vi.fn(),
+  decide: vi.fn(),
   hasPermission: vi.fn(),
 }));
 
@@ -275,6 +276,13 @@ describe("agent issue mutation checkout ownership", () => {
     registerRouteMocks();
     vi.clearAllMocks();
     mockAccessService.canUser.mockReset();
+    mockAccessService.decide.mockReset();
+    mockAccessService.decide.mockImplementation(async (input: { action: string }) => ({
+      allowed: input.action === "tasks:assign",
+      action: input.action,
+      reason: input.action === "tasks:assign" ? "allow_explicit_grant" : "deny_missing_grant",
+      explanation: input.action === "tasks:assign" ? "Allowed by test assignment default." : "Missing permission.",
+    }));
     mockAccessService.hasPermission.mockReset();
     mockAgentService.getById.mockReset();
     mockAgentService.list.mockReset();
@@ -682,12 +690,12 @@ describe("agent issue mutation checkout ownership", () => {
   });
 
   it("allows agents with the active-checkout management grant to mutate active checkouts", async () => {
-    mockAccessService.hasPermission.mockImplementation(async (
-      _companyId: string,
-      _principalType: string,
-      principalId: string,
-      permissionKey: string,
-    ) => principalId === peerAgentId && permissionKey === "tasks:manage_active_checkouts");
+    mockAccessService.decide.mockImplementation(async (input: { action: string }) => ({
+      allowed: input.action === "tasks:manage_active_checkouts",
+      action: input.action,
+      reason: input.action === "tasks:manage_active_checkouts" ? "allow_explicit_grant" : "deny_missing_grant",
+      explanation: input.action === "tasks:manage_active_checkouts" ? "Allowed by checkout management grant." : "Missing permission.",
+    }));
 
     const res = await request(await createApp(peerActor())).patch(`/api/issues/${issueId}`).send({ title: "Managed update" });
 
@@ -828,4 +836,37 @@ describe("agent issue mutation checkout ownership", () => {
       }),
     );
   });
+
+  it("uses the authorization decision path for assignment changes", async () => {
+    const decide = vi.fn(async () => ({
+      allowed: false,
+      action: "tasks:assign",
+      reason: "deny_policy_restricted",
+      explanation: "Target agent requires approval before task assignment.",
+    }));
+    (mockAccessService as any).decide = decide;
+    mockIssueService.getById.mockResolvedValue(makeIssue({ assigneeAgentId: ownerAgentId }));
+    mockAgentService.resolveByReference.mockResolvedValue({
+      ambiguous: false,
+      agent: makeAgent(peerAgentId),
+    });
+
+    const app = await createApp(ownerActor());
+    const res = await request(app)
+      .patch(`/api/issues/${issueId}`)
+      .send({ assigneeAgentId: peerAgentId });
+
+    expect(res.status).toBe(403);
+    expect(res.body.error).toContain("requires approval");
+    expect(decide).toHaveBeenCalledWith(expect.objectContaining({
+      action: "tasks:assign",
+      resource: expect.objectContaining({
+        type: "issue",
+        companyId,
+        issueId,
+        assigneeAgentId: peerAgentId,
+      }),
+    }));
+    expect(mockIssueService.update).not.toHaveBeenCalled();
+  });
 });