feat(delivery): production deploy over SSH/SFTP/FTP/FTPS (v2 phase A3-5)

The one path that touches a customer's server, and the one the platform cannot
undo. It is human-triggered, confirmed and audited; there is deliberately no
code path from a pipeline run into it (D13).

- deploy_ssh.py: SshDeployer. Release lands in releases/<ts>-<sha7>/, the
  post-deploy command runs with cwd there, and only then does `current` move —
  atomically (relative symlink + mv -T). A failed hook or extraction never moves
  it, so the previous release keeps serving. Host key is pinned on first success
  (TOFU); a mismatch is a hard failure. Prunes to the newest five.
- deploy_ftp.py: FtpDeployer. FTP has no atomic switch and no rollback except a
  backup, so a backup is mandatory: every file about to be overwritten is
  archived under ARTIFACTS_ROOT before anything is uploaded. The artifact is
  extracted, then the build dir (dist/build/public/out) is chosen — a static
  deploy must not publish the repository. Archive members are sanitised: absolute
  paths, `..` and escaping links are refused.
- deploy_target.py: the tester that dispatches on `kind`.
- deploy_service.py + production_deploys (migration a3b4c5d6e7f4) + 4 routes.
  One deploy per project at a time; the org slug must be typed back; the target
  summary reports has_secret, never the secret.

Tests: 499 API (+26) with fake SSH/FTP transports; ruff, mypy, alembic clean.

Report: docs/plan/reports/agent-3-phase-5.md

apps/api/app/application/container.py

@@ -18,6 +18,7 @@ from sqlalchemy.ext.asyncio import AsyncSession
 from app.application.container_delivery import (
     build_delivery_hooks,
     build_delivery_service,
+    build_deploy_service,
     build_deploy_target_tester,
     build_repo_workspace,
 )
@@ -168,6 +169,7 @@ __all__ = [
     "build_billing_service",
     "build_delivery_hooks",
     "build_delivery_service",
+    "build_deploy_service",
     "build_deploy_target_tester",
     "build_memory",
     "build_model_grants",