create-adapter

# Create Adapter ## Why Performance Matters Adapters are the largest performance risk in Sidecar. Conversations refresh on watch events in a hot path that runs continuously during active sessions: ``` watch event -> coalescer -> session refresh -> adapter.Sessions() -> metadata parsing ``` If an adapter does full directory scans and full-file reparses on every change, CPU and FD usage spike quickly. ## Reference Adapters Study these before writing a new adapter: - `internal/adapter/claudecode` - Incremental JSONL parsing, targeted refresh - `internal/adapter/codex` - Directory cache, two-pass metadata parsing, global watch scope - `internal/adapter/cursor` - SQLite/WAL-aware cache invalidation, FD-safe DB access - `internal/adapter/pi` - Global scope, JSONL, CWD-based filtering, session classification, message prefix stripping ## Required Interface All adapters implement `adapter.Adapter`: ```go type Adapter interface { ID() string Name() string Icon() string Detect(projectRoot string) (bool, error) Capabilities() CapabilitySet Sessions(projectRoot string) ([]Session, error) Messages(sessionID string) ([]Message, error) Usage(sessionID string) (*UsageStats, error) Watch(projectRoot string) (<-chan Event, io.Closer, error) } ``` ### Required Session Fields Every session from `Sessions()` must set: - `ID`, `Name` - `AdapterID`, `AdapterName`, `AdapterIcon` - `CreatedAt`, `UpdatedAt` - `MessageCount`, `FileSize` `FileSize` is used ...