Add terminal session management with heartbeat monitoring, idle timeout detection, session reuse logic, and command history panel UI with search and filtering capabilities

app/schemas/terminal.py

@@ -2,11 +2,55 @@
 Pydantic schemas for terminal session API.
 """
 from datetime import datetime
-from typing import Optional, Literal
+from typing import List, Optional, Literal, Any
 
 from pydantic import BaseModel, Field
 
 
+# ============================================================================
+# Command History Schemas
+# ============================================================================
+
+class CommandHistoryItem(BaseModel):
+    """A single command from history."""
+    id: int
+    command: str
+    created_at: datetime
+    host_name: Optional[str] = None
+    username: Optional[str] = None
+    execution_count: Optional[int] = None
+    
+    class Config:
+        from_attributes = True
+
+
+class CommandHistoryResponse(BaseModel):
+    """Response containing command history."""
+    commands: List[CommandHistoryItem]
+    total: int
+    host_id: Optional[str] = None
+    query: Optional[str] = None
+
+
+class UniqueCommandItem(BaseModel):
+    """A unique command with usage stats."""
+    command: str
+    command_hash: str
+    last_used: datetime
+    execution_count: int
+
+
+class UniqueCommandsResponse(BaseModel):
+    """Response containing unique commands."""
+    commands: List[UniqueCommandItem]
+    total: int
+    host_id: str
+
+
+# ============================================================================
+# Terminal Session Schemas
+# ============================================================================
+
 class TerminalSessionRequest(BaseModel):
     """Request to create a new terminal session."""
     mode: Literal["embedded", "popout"] = Field(
@@ -33,16 +77,23 @@ class TerminalSessionResponse(BaseModel):
     ttl_seconds: int
     mode: str
     host: TerminalSessionHost
+    reused: bool = False  # True if an existing session was reused
+    token: Optional[str] = None  # Only provided for new sessions
 
 
 class TerminalSessionStatus(BaseModel):
     """Current status of a terminal session."""
     session_id: str
     status: str
+    host_id: str
     host_name: str
+    mode: str = "embedded"
     created_at: datetime
     expires_at: datetime
+    last_seen_at: Optional[datetime] = None
     remaining_seconds: int
+    age_seconds: int = 0
+    last_seen_seconds: int = 0
 
 
 class TerminalSessionList(BaseModel):
@@ -50,3 +101,57 @@ class TerminalSessionList(BaseModel):
     sessions: list[TerminalSessionStatus]
     total: int
     max_per_user: int
+
+
+class ActiveSessionInfo(BaseModel):
+    """Info about an active session for limit error response."""
+    session_id: str
+    host_id: str
+    host_name: str
+    mode: str
+    age_seconds: int
+    last_seen_seconds: int
+
+
+class SessionLimitError(BaseModel):
+    """Rich error response when session limit is exceeded."""
+    error: str = "SESSION_LIMIT"
+    message: str
+    max_active: int
+    current_count: int
+    active_sessions: List[ActiveSessionInfo]
+    suggested_actions: List[str]
+    can_reuse: bool = False
+    reusable_session_id: Optional[str] = None
+
+
+class HeartbeatRequest(BaseModel):
+    """Request to update session heartbeat."""
+    pass  # Empty body, session_id comes from path
+
+
+class HeartbeatResponse(BaseModel):
+    """Response from heartbeat endpoint."""
+    session_id: str
+    status: str
+    last_seen_at: datetime
+    remaining_seconds: int
+    healthy: bool = True
+
+
+class CloseBeaconRequest(BaseModel):
+    """Request from sendBeacon to close session."""
+    reason: str = "client_close"
+
+
+class SessionMetrics(BaseModel):
+    """Terminal session service metrics."""
+    sessions_created: int
+    sessions_reused: int
+    sessions_closed_user: int
+    sessions_gc_expired: int
+    sessions_gc_idle: int
+    session_limit_hits: int
+    active_processes: int
+    allocated_ports: int
+    gc_running: bool