feat: implement OpsCatalog extension (BRIDGE-WP-0002)

Adds the OpsCatalog subsystem: a Git-backed YAML catalog of operations
domains, targets, bridges, and actor classes. Includes catalog loader,
cross-reference validator, bridge resolver (inline-first, catalog
fallback), and new CLI commands: `bridge targets`, `bridge targets show`,
`bridge catalog list/validate/show`. Updates `up/down/restart` to resolve
bridge names from the catalog when not defined inline. 142 tests, all green.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/bridge/config.py

@@ -4,7 +4,7 @@ from __future__ import annotations
 import os
 from dataclasses import dataclass
 from pathlib import Path
-from typing import Dict
+from typing import Dict, Optional
 
 import yaml
 
@@ -19,6 +19,7 @@ class ConfigError(Exception):
 class BridgeConfig:
     tunnels: Dict[str, TunnelConfig]
     actors: Dict[str, ActorInfo]
+    catalog_path: Optional[Path] = None
 
 
 def _default_config_path() -> Path:
@@ -43,7 +44,12 @@ def load_config() -> BridgeConfig:
 
     tunnels = _parse_tunnels(raw.get("tunnels") or {})
     actors = _parse_actors(raw.get("actors") or {})
-    return BridgeConfig(tunnels=tunnels, actors=actors)
+
+    catalog_path = None
+    if "catalog_path" in raw and raw["catalog_path"]:
+        catalog_path = Path(os.path.expanduser(str(raw["catalog_path"])))
+
+    return BridgeConfig(tunnels=tunnels, actors=actors, catalog_path=catalog_path)
 
 
 def _parse_tunnels(raw: dict) -> Dict[str, TunnelConfig]: