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/src/castle_core/manifest.py

@@ -5,7 +5,7 @@ from __future__ import annotations
 from enum import Enum
 from typing import Annotated, Literal, Union
 
-from pydantic import BaseModel, ConfigDict, Field, model_validator
+from pydantic import AliasChoices, BaseModel, ConfigDict, Field, model_validator
 
 EnvMap = dict[str, str]
 
@@ -247,8 +247,13 @@ class ProgramSpec(BaseModel):
 class ServiceSpec(BaseModel):
     """Long-running daemon deployment config."""
 
+    model_config = ConfigDict(populate_by_name=True)
+
     id: str = ""
-    component: str | None = None
+    # The program this service deploys. (`component` accepted as a legacy alias.)
+    program: str | None = Field(
+        default=None, validation_alias=AliasChoices("program", "component")
+    )
     description: str | None = None
 
     run: RunSpec
@@ -274,8 +279,13 @@ class ServiceSpec(BaseModel):
 class JobSpec(BaseModel):
     """Scheduled task that runs periodically and exits."""
 
+    model_config = ConfigDict(populate_by_name=True)
+
     id: str = ""
-    component: str | None = None
+    # The program this job runs. (`component` accepted as a legacy alias.)
+    program: str | None = Field(
+        default=None, validation_alias=AliasChoices("program", "component")
+    )
     description: str | None = None
 
     run: RunSpec