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/src/castle_api/nodes.py

@@ -6,7 +6,7 @@ from fastapi import APIRouter, HTTPException, Request, status
 
 from castle_api.config import get_registry, settings
 from castle_api.mesh import mesh_state
-from castle_api.models import ComponentSummary, MeshStatus, NodeDetail, NodeSummary
+from castle_api.models import DeploymentSummary, MeshStatus, NodeDetail, NodeSummary
 
 router = APIRouter(tags=["nodes"])
 
@@ -39,12 +39,12 @@ def _remote_node_summary(hostname: str, remote: object) -> NodeSummary:
     )
 
 
-def _deployed_to_summaries(registry: object, hostname: str) -> list[ComponentSummary]:
-    """Convert deployed components from a registry into ComponentSummary list."""
+def _deployed_to_summaries(registry: object, hostname: str) -> list[DeploymentSummary]:
+    """Convert deployed components from a registry into DeploymentSummary list."""
     summaries = []
     for name, d in registry.deployed.items():
         summaries.append(
-            ComponentSummary(
+            DeploymentSummary(
                 id=name,
                 category="job" if d.schedule else "service",
                 description=d.description,