feat(connections): add self-serve intent runtime (#12345)

## Thinking Path

> - Paperclip is the open source app people use to manage AI agents for
work.
> - Agents need a governed way to request app connections during issue
work.
> - The catalog now describes the available providers and setup methods.
> - A request must become a durable, company-scoped intent before an
operator acts on it.
> - This pull request adds that intent runtime across server, agent,
CLI, and shared contracts.
> - The benefit is a safe bridge from agent need to operator-approved
setup.

## Linked Issues or Issue Description

Refs #11965

This is stack 7 of 11. It depends on stack 6 and replaces another
reviewable part of #11965.

## What Changed

- Add connection intent types, validation, service logic, and routes.
- Add agent runtime tools and CLI support for connection requests.
- Add issue-thread interaction support for connection intents.
- Add runtime, route, adapter, and contract tests.
- Hold the final resolved-continuation row lock through asynchronous
adapter preparation until an actual process spawn, so parking or
reassignment cannot cross that boundary.
- Report Hermes Gateway's first remote run request through the shared
dispatch hook so the resolved-intent lock is released at the true
dispatch boundary.
- Revalidate the addressed user's live non-viewer membership and
connection-management authority for every intent mutation, including
OAuth completion.

## Verification

- `pnpm --filter @paperclipai/server typecheck`
- `pnpm --filter @paperclipai/server exec vitest run
src/__tests__/tool-access-service.test.ts`
- Result: 176 tests passed.
- `pnpm build`
- `pnpm --filter @paperclipai/server exec vitest run
src/__tests__/heartbeat-stale-queue-invalidation.test.ts` (32 passed;
includes non-process dispatch lock-release coverage)
- `pnpm exec vitest run --project @paperclipai/server
server/src/__tests__/connection-intents-service.test.ts -t
"addressed-user mutation"` (1 passed)
- `pnpm exec vitest run --project @paperclipai/server
server/src/__tests__/tool-access-service.test.ts -t "binds OAuth
callback completion to the initiating board session"` (1 passed)
- `pnpm --filter @paperclipai/hermes-paperclip-adapter test --
src/gateway/server/execute.test.ts` (23 passed; includes dispatch-hook
ordering and exactly-once coverage)
- `pnpm --filter @paperclipai/hermes-paperclip-adapter typecheck`

## Risks

- A malformed intent could create an unusable operator request.
- Validators and company checks reject invalid or cross-company
requests.
- The final continuation gate holds the issue row lock through adapter
preparation until process or remote dispatch; later operator changes use
the normal active-run interruption path.
- The change does not add a database migration.

> I checked `ROADMAP.md`. This stack continues the existing app
connection work from #11965 and does not duplicate another planned item.

## Model Used

OpenAI Codex, GPT-5. The runtime model ID and context window were not
exposed. The model used reasoning, tool use, and code execution.

## 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 linked the public source pull request with `Refs #`
- [x] I have not referenced internal or instance-local Paperclip issues
or links
- [x] My branch name describes the change and contains no internal
Paperclip ticket id or instance-derived details
- [x] I have run tests locally and they pass
- [x] I have added or updated tests where applicable
- [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>

server/src/middleware/auth.ts

@@ -211,6 +211,8 @@ interface ActorMiddlewareOptions {
   resolveSession?: (req: Request) => Promise<BetterAuthSessionResult | null>;
 }
 
+const publicMcpGatewayProtocolPath = /^\/mcp\/gateways\/gw_[a-f0-9]{32}\/?$/i;
+
 export function actorMiddleware(db: Db, opts: ActorMiddlewareOptions): RequestHandler {
   const boardAuth = boardAuthService(db);
   return async (req, _res, next) => {
@@ -230,6 +232,19 @@ export function actorMiddleware(db: Db, opts: ActorMiddlewareOptions): RequestHa
 
     const authHeader = req.header("authorization");
     const hasBearerCredentials = /^bearer(?:\s|$)/i.test(authHeader ?? "");
+
+    // Public MCP gateway protocol requests carry a pcgw_* bearer that is
+    // validated by the gateway service itself. Do not interpret that bearer as
+    // a board key or agent JWT here: doing so rejects the MCP handshake before
+    // the protocol route can verify its run-scoped credential. Keep this bypass
+    // restricted to the unguessable public gateway path; all /api routes retain
+    // the normal actor authentication path below.
+    if (hasBearerCredentials && publicMcpGatewayProtocolPath.test(req.path)) {
+      if (runIdHeader) req.actor.runId = runIdHeader;
+      next();
+      return;
+    }
+
     if (!hasBearerCredentials) {
       if (opts.deploymentMode === "authenticated" && opts.resolveSession) {
         const cloudTenantActor = await resolveCloudTenantActor(db, req);