feat: terminal startup command and container tools

- Add startup_command field to ToolType model and API
- Execute startup command before interactive shell in terminal sessions
- Add tmux and ranger to OpenCode container spec
- Update Tool Workshop UI with startup_command input for terminal types
- Add backend tests for startup_command CRUD operations
- Sync specs: tool-terminal, tool-types-definition, opencode-web-server
- New spec: tool-terminal-startup-command

Quality gates: Frontend typecheck/lint passed. Backend tests blocked by environment (Python/Docker not available).

OpenSpec: terminal-startup-and-container-tools

openspec/specs/tool-terminal/spec.md

@@ -16,6 +16,19 @@ The system SHALL provide terminal sessions via WebSocket.
 - THEN a WebSocket connection is established
 - AND a shell is spawned in the container via `docker exec`
 
+#### Scenario: Open terminal with startup command
+- GIVEN a running tool instance with a tool type that has `startup_command` set
+- WHEN the user opens the terminal
+- THEN a WebSocket connection is established
+- AND the startup command is executed before the interactive shell
+- AND the shell is spawned in the container via `docker exec`
+
+#### Scenario: Open terminal without startup command
+- GIVEN a running tool instance with a tool type that has no `startup_command`
+- WHEN the user opens the terminal
+- THEN a WebSocket connection is established
+- AND the shell spawns directly without any startup execution
+
 ### Requirement: Terminal I/O
 
 The system SHALL stream terminal I/O via WebSocket.
@@ -51,6 +64,12 @@ The system SHALL manage terminal sessions.
 - THEN the session is cleaned up
 - AND the shell process is terminated
 
+#### Scenario: Reset terminal session runs startup command
+- GIVEN an active terminal session
+- WHEN the user resets the session
+- THEN a new shell is spawned
+- AND the startup command executes before the new interactive shell
+
 ### Requirement: Access Control
 
 The system SHALL restrict terminal access.