feat: implement OpsBridge CLI (BRIDGE-WP-0001)

Full TDD implementation of the `bridge` CLI tool covering all phases
from BRIDGE-WP-0001: project scaffolding, config loading, state
management, audit logging, health checks, tunnel lifecycle manager, and
all CLI commands (up/down/restart/status/logs). 77 tests, all green.

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

src/bridge/models.py

@@ -0,0 +1,49 @@
+"""Domain models for OpsBridge."""
+from __future__ import annotations
+
+from dataclasses import dataclass, field
+from enum import Enum
+from typing import Optional
+
+
+class BridgeState(str, Enum):
+    STOPPED = "stopped"
+    STARTING = "starting"
+    CONNECTED = "connected"
+    DEGRADED = "degraded"
+    RECONNECTING = "reconnecting"
+    FAILED = "failed"
+
+
+@dataclass
+class ReconnectPolicy:
+    max_attempts: int = 0  # 0 = infinite
+    backoff_initial: int = 5
+    backoff_max: int = 60
+
+
+@dataclass
+class HealthCheckConfig:
+    url: str
+    interval_seconds: int = 30
+    timeout_seconds: int = 5
+
+
+@dataclass
+class TunnelConfig:
+    name: str
+    host: str
+    remote_port: int
+    local_port: int
+    ssh_user: str
+    ssh_key: str
+    actor: str
+    reconnect: ReconnectPolicy = field(default_factory=ReconnectPolicy)
+    health_check: Optional[HealthCheckConfig] = None
+
+
+@dataclass
+class ActorInfo:
+    name: str
+    actor_class: str  # "human" or "automation"
+    description: str = ""