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/fieldSchemas.ts

@@ -23,6 +23,10 @@ export const INTEGRATION_FIELDS: Partial<Record<IntegrationType, IntegrationFiel
     { key: "url", label: "Dockhand URL", secret: false, placeholder: "https://dockhand.example.lan" },
     { key: "token", label: "API token", secret: true, type: "password", placeholder: "dh_..." },
   ],
+  semaphore: [
+    { key: "url", label: "Semaphore URL", secret: false, placeholder: "https://semaphore.example.lan" },
+    { key: "token", label: "API token", secret: true, type: "password" },
+  ],
 };
 
 /** Fixed base URL per integration type, stored on the row for display/reference. */