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.

castle-api/tests/test_mesh.py

@@ -2,7 +2,7 @@
 
 import time
 
-from castle_core.registry import DeployedComponent, NodeConfig, NodeRegistry
+from castle_core.registry import Deployment, NodeConfig, NodeRegistry
 
 from castle_api.mesh import STALE_TTL_SECONDS, MeshStateManager, RemoteNode
 
@@ -96,7 +96,7 @@ class TestMeshStateManager:
         mgr.update_node("devbox", _make_registry("devbox"))
         new_reg = _make_registry(
             "devbox",
-            {"svc": DeployedComponent(runner="python", run_cmd=["svc"])},
+            {"svc": Deployment(runner="python", run_cmd=["svc"])},
         )
         mgr.update_node("devbox", new_reg)
         node = mgr.get_node("devbox")