Add Semaphore integration

Fourth live integration: Ansible run history per template with a
trigger-a-run action — matching the "dashboard + basic actions" depth from
the plan. Adapter built against Semaphore's official published OpenAPI spec
(github.com/semaphoreui/semaphore/blob/develop/api-docs.yml) plus its Go
source directly for the task-status enum, which the spec itself leaves
untyped (db/Task.go, pkg/task_logger/task_logger.go) — instance wasn't
reachable from here (semaphore.int.toolabs.se doesn't resolve outside the
user's LAN), so verified against the real spec/source rather than guessing.

server/src/integrations/semaphore/adapter.ts: GET /api/projects, then GET
/api/project/{id}/templates?sort=name&order=asc per project — each template
in that response already embeds its last_task, so listing every template's
current status across every project needs only one call per project (no
N+1 per-template lookup, unlike Gitea where the run history isn't embedded
in the repo list). POST /api/project/{id}/tasks {template_id} triggers a
run. Follows the same config-in-UI + encrypted-credential pattern as the
other three integrations.

Verified: full build passes. Same as Dockhand — unreachable, so ran a
14-check HTTP test against the live server (real target URL, bogus token):
role gating, credential non-leakage, disabled-integration blocking, and the
wrong_type crash-safety check for this fourth adapter type, confirming the
server stays up throughout. Real template/run data and the trigger-a-run
action still need verification once this app can reach the user's LAN.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

server/src/integrations/registry.ts

@@ -3,6 +3,7 @@ import type { IntegrationConfig } from "./types.js";
 import { createTailscaleAdapter } from "./tailscale/adapter.js";
 import { createGiteaAdapter } from "./gitea/adapter.js";
 import { createDockhandAdapter } from "./dockhand/adapter.js";
+import { createSemaphoreAdapter } from "./semaphore/adapter.js";
 
 export interface PingableAdapter {
   ping(): Promise<{ ok: boolean; latencyMs?: number; error?: string }>;
@@ -23,6 +24,8 @@ export function createIntegrationAdapter(type: IntegrationType, config: Integrat
       return createGiteaAdapter(config as any);
     case "dockhand":
       return createDockhandAdapter(config as any);
+    case "semaphore":
+      return createSemaphoreAdapter(config as any);
     default:
       throw new Error(`Integration type "${type}" is not implemented yet`);
   }