[codex] Bundle local branch fixes from PAP-10032 (#6604)

## Thinking Path

> - Paperclip orchestrates AI agents for zero-human companies.
> - This branch accumulated multiple already-tested control-plane,
adapter runtime, invite, workspace, plugin, and UI quality fixes on the
primary Paperclip checkout.
> - `origin/master` advanced while those commits were still local, so
the branch needed to be preserved and reconciled before review.
> - Splitting the branch commit-by-commit against the new base produced
overlapping conflicts with recently merged upstream PRs.
> - This pull request keeps the remaining branch as one standalone PR
because the final diff is 38 files after removing screenshot artifacts,
under Greptile's 100-file cap, and can be merged independently after
review.
> - The benefit is that none of the local work is lost, the branch is
now based on current `origin/master`, and reviewers can evaluate the
reconciled changes in one place.

## What Changed

- Merged the local accumulated branch with current `origin/master` and
resolved the invite-flow overlaps from the newer upstream companies
query helper.
- Preserved the local fixes for invite existing-member behavior, invite
link copy fallback, reusable workspace selection, worktree auth, static
SPA fallback, markdown wrapping, plugin slot registration, cloud
upstream UX/server polish, project sorting, and related tests.
- Removed screenshot artifacts from the PR per review request.
- Kept the PR under the requested file limit: 38 files changed, with no
`pnpm-lock.yaml` or `.github/workflows/*` changes.

## Verification

- `NODE_ENV=test pnpm exec vitest run
ui/src/pages/CompanyInvites.test.tsx ui/src/pages/InviteLanding.test.tsx
ui/src/pages/Projects.test.tsx ui/src/plugins/slots.test.ts
ui/src/components/MarkdownBody.test.tsx
server/src/__tests__/invite-accept-existing-member.test.ts
server/src/__tests__/static-index-html.test.ts
server/src/__tests__/execution-workspaces-service.test.ts
server/src/__tests__/better-auth.test.ts
server/src/__tests__/worktree-config.test.ts`
- `NODE_ENV=test pnpm --filter @paperclipai/ui typecheck`
- `NODE_ENV=test pnpm --filter @paperclipai/server typecheck`
- Confirmed `git diff --name-only origin/master...HEAD | wc -l` is `38`.
- Confirmed no PR diff entries match `pnpm-lock.yaml`,
`.github/workflows/*`, or `screenshots/*`.

## Risks

- Medium review risk because this is a bundled rescue PR rather than
several narrow feature PRs.
- Invite flow and company cache behavior overlapped with newer upstream
changes; the merge resolution intentionally keeps the shared
`companiesListQueryOptions` helper while preserving local
existing-member invite behavior.
- Visual review evidence is no longer attached in-repo because
screenshots were removed from this PR per review request.

> 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-based coding agent, with repository tool access,
terminal execution, and git/GitHub CLI operations.

## 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] UI screenshots were intentionally removed from this PR per review
request
- [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>
Co-authored-by: Claude Opus 4.7 <noreply@anthropic.com>
Co-authored-by: CodexCoder <codexcoder@paperclip.local>

ui/src/plugins/slots.test.ts

@@ -0,0 +1,87 @@
+// @vitest-environment jsdom
+
+import { createElement } from "react";
+import { flushSync } from "react-dom";
+import { createRoot, type Root } from "react-dom/client";
+import { afterEach, describe, expect, it } from "vitest";
+import {
+  PluginSlotMount,
+  _collectRegisterableExportNamesForTests,
+  _resetPluginModuleLoader,
+  registerPluginWebComponent,
+  type ResolvedPluginSlot,
+} from "./slots";
+
+let roots: Root[] = [];
+
+afterEach(() => {
+  for (const root of roots) {
+    flushSync(() => {
+      root.unmount();
+    });
+  }
+  roots = [];
+  _resetPluginModuleLoader();
+});
+
+describe("plugin slot export registration", () => {
+  it("keeps declared missing exports visible for diagnostics", () => {
+    const exports = _collectRegisterableExportNamesForTests(
+      { Page: () => null },
+      new Set(["Page", "MissingRouteSidebar"]),
+    );
+
+    expect([...exports]).toEqual(["Page", "MissingRouteSidebar"]);
+  });
+
+  it("registers component-like module exports even when the current contribution did not declare them", () => {
+    const exports = _collectRegisterableExportNamesForTests(
+      {
+        Page: () => null,
+        RouteSidebar: () => null,
+        webComponentTag: "paperclip-widget",
+        metadata: { ignored: true },
+        count: 1,
+        default: () => null,
+      },
+      new Set(["Page"]),
+    );
+
+    expect(exports).toEqual(new Set(["Page", "RouteSidebar", "webComponentTag"]));
+  });
+
+  it("updates an already-mounted placeholder when the slot export registers later", async () => {
+    const container = document.createElement("div");
+    document.body.appendChild(container);
+    const root = createRoot(container);
+    roots.push(root);
+    const slot: ResolvedPluginSlot = {
+      type: "routeSidebar",
+      id: "content-machine-sidebar",
+      displayName: "Content",
+      exportName: "ContentMachineRouteSidebar",
+      routePath: "content-machine",
+      pluginId: "content-machine-plugin",
+      pluginKey: "content-machine",
+      pluginDisplayName: "Content Machine",
+      pluginVersion: "1.0.0",
+    };
+
+    flushSync(() => {
+      root.render(createElement(PluginSlotMount, {
+        slot,
+        context: { companyId: "company-1", companyPrefix: "PAP" },
+        missingBehavior: "placeholder",
+      }));
+    });
+
+    expect(container.textContent).toContain("Content Machine: Content");
+
+    flushSync(() => {
+      registerPluginWebComponent("content-machine", "ContentMachineRouteSidebar", "paperclip-test-sidebar");
+    });
+
+    expect(container.textContent).not.toContain("Content Machine: Content");
+    expect(container.querySelector("paperclip-test-sidebar")).not.toBeNull();
+  });
+});

ui/src/plugins/slots.tsx

@@ -124,11 +124,30 @@ type UsePluginSlotsResult = {
  * Keys are `${pluginKey}:${exportName}` to match manifest slot declarations.
  */
 const registry = new Map<string, RegisteredPluginComponent>();
+const registryListeners = new Set<() => void>();
 
 function buildRegistryKey(pluginKey: string, exportName: string): string {
   return `${pluginKey}:${exportName}`;
 }
 
+function notifyRegistryListeners(): void {
+  for (const listener of registryListeners) {
+    listener();
+  }
+}
+
+function usePluginRegistrySubscription(): void {
+  const [, forceRerender] = useState(0);
+
+  useEffect(() => {
+    const listener = () => forceRerender((tick) => tick + 1);
+    registryListeners.add(listener);
+    return () => {
+      registryListeners.delete(listener);
+    };
+  }, []);
+}
+
 function requiresEntityType(slotType: PluginUiSlotType): boolean {
   return slotType === "detailTab" || slotType === "taskDetailView" || slotType === "contextMenuItem" || slotType === "commentAnnotation" || slotType === "commentContextMenuItem" || slotType === "projectSidebarItem" || slotType === "toolbarButton";
 }
@@ -150,6 +169,7 @@ export function registerPluginReactComponent(
     kind: "react",
     component,
   });
+  notifyRegistryListeners();
 }
 
 /**
@@ -164,6 +184,7 @@ export function registerPluginWebComponent(
     kind: "web-component",
     tagName,
   });
+  notifyRegistryListeners();
 }
 
 function resolveRegisteredComponent(slot: ResolvedPluginSlot): RegisteredPluginComponent | null {
@@ -177,6 +198,24 @@ export function resolveRegisteredPluginComponent(
   return registry.get(buildRegistryKey(pluginKey, exportName)) ?? null;
 }
 
+function isRegisterablePluginExport(exported: unknown): boolean {
+  return typeof exported === "function" || typeof exported === "string";
+}
+
+function collectRegisterableExportNames(
+  mod: Record<string, unknown>,
+  declaredExports: Set<string>,
+): Set<string> {
+  const exportNames = new Set(declaredExports);
+  for (const [exportName, exported] of Object.entries(mod)) {
+    if (exportName === "default") continue;
+    if (isRegisterablePluginExport(exported)) {
+      exportNames.add(exportName);
+    }
+  }
+  return exportNames;
+}
+
 // ---------------------------------------------------------------------------
 // Plugin module dynamic import loader
 // ---------------------------------------------------------------------------
@@ -471,7 +510,8 @@ async function loadPluginModule(contribution: PluginUiContribution): Promise<voi
         }
       }
 
-      for (const exportName of declaredExports) {
+      const exportNames = collectRegisterableExportNames(mod, declaredExports);
+      for (const exportName of exportNames) {
         const exported = mod[exportName];
         if (exported === undefined) {
           console.warn(
@@ -783,6 +823,7 @@ export function PluginSlotMount({
   className,
   missingBehavior = "hidden",
 }: PluginSlotMountProps) {
+  usePluginRegistrySubscription();
   const [, forceRerender] = useState(0);
   const component = resolveRegisteredComponent(slot);
 
@@ -910,3 +951,4 @@ export function _resetPluginModuleLoader(): void {
 export const _applyJsxRuntimeKeyForTests = applyJsxRuntimeKey;
 export const _createReactShimSourceForTests = createReactShimSource;
 export const _rewriteBareSpecifiersForTests = rewriteBareSpecifiers;
+export const _collectRegisterableExportNamesForTests = collectRegisterableExportNames;