refactor: Align vocabulary — component → program / deployment

Canonical terms (see docs/registry.md glossary):
- program: any catalog entry (tool/daemon/frontend) — the software
- service / job: how a program is deployed (systemd .service / .timer)
- deployment: umbrella for the unified service+job+program view

Changes:
- core: ServiceSpec/JobSpec component: → program: (component accepted as
  back-compat validation_alias); DeployedComponent → Deployment.
- api: ComponentSummary/Detail → DeploymentSummary/Detail; GET /components
  → /deployments; GatewayRoute.component → program; GatewayInfo
  .component_count → deployment_count; ServiceActionResponse/action keys
  component → program.
- app: matching type renames, /components → /deployments hook, route
  /component/:name → /deployment/:name, GatewayRoute.program.
- docs: component-registry.md → registry.md (+ canonical glossary);
  CLAUDE.md endpoint list refreshed (drop removed /tools, add typed
  program/service/job + config routes).

Tests: core 92, cli 24, api 52 green; app build clean; ruff clean.

core/tests/test_deploy_prune.py

@@ -7,11 +7,11 @@ from unittest.mock import patch
 
 from castle_core import deploy as deploy_mod
 from castle_core.deploy import _desired_unit_files, _prune_orphans
-from castle_core.registry import DeployedComponent, NodeConfig, NodeRegistry
+from castle_core.registry import Deployment, NodeConfig, NodeRegistry
 
 
-def _svc(managed: bool = True, schedule: str | None = None) -> DeployedComponent:
-    return DeployedComponent(
+def _svc(managed: bool = True, schedule: str | None = None) -> Deployment:
+    return Deployment(
         runner="python",
         run_cmd=["x"],
         env={},
@@ -20,7 +20,7 @@ def _svc(managed: bool = True, schedule: str | None = None) -> DeployedComponent
     )
 
 
-def _registry(**deployed: DeployedComponent) -> NodeRegistry:
+def _registry(**deployed: Deployment) -> NodeRegistry:
     return NodeRegistry(node=NodeConfig(castle_root="/x", gateway_port=9000), deployed=dict(deployed))