Add OpenCode as the 4th supported application with additive provider management:
- Add OpenCode variant to AppType enum with all related match statements
- Add enabled_opencode field to McpApps and SkillApps structures
- Add opencode field to McpRoot and PromptRoot
- Add database schema migration v3→v4 with enabled_opencode columns
- Add settings.rs support for opencode_config_dir and current_provider_opencode
- Create opencode_config.rs module for config file I/O operations
- Update all services (proxy, mcp, skill, provider, stream_check) for OpenCode
- Add OpenCode support to deeplink provider and MCP parsing
- Update commands/config.rs for OpenCode config status and paths
Key design decisions:
- OpenCode uses additive mode (no is_current needed, no proxy support)
- Config path: ~/.config/opencode/opencode.json
- MCP format: stdio→local, sse/http→remote conversion planned
- Stream check returns error (not yet implemented for OpenCode)
Fix backfill logic in prompt enable workflow:
- Prioritize backfilling live file content to currently enabled prompt (prevent data loss)
- Create backup only when no enabled prompt exists and content is new (avoid duplicate backups)
- Implement staged persistence (save after backfill + save after enable)
- Add explicit logging for backfill/backup operations
Also simplify string formatting in prompt_files.rs with inline format strings.
Address code review feedback for PR #214:
- Replace hardcoded Chinese strings with English in auto-imported prompts
- Prompt name: "Auto-imported Prompt" instead of "初始提示词"
- Description: "Automatically imported on first launch"
- Remove panic risk by replacing expect() with proper error propagation
- Use AppError::localized for bilingual error messages
- Extract get_base_dir_with_fallback() helper to eliminate code duplication
- Update test assertions to match new English strings
- Suppress false-positive dead_code warning on TempHome.dir field
All 5 tests passing with zero compiler warnings.
- Extract prompt file path logic to dedicated prompt_files module
- Refactor PromptService to use centralized path resolution
- Implement auto-import for existing prompt files on first startup
- Add comprehensive unit tests for auto-import functionality
Jason