feat: import and resume Claude Code CLI sessions (closes #10)

[liuxiaopai-ai]

Summary

Implements the ability to browse and import conversation history from Claude Code CLI into CodePilot, with full resume support. This closes #10.

Problem

Users who have been using Claude Code CLI have accumulated conversation history stored as JSONL files in ~/.claude/projects/. There was no way to view or continue these conversations in CodePilot.

Solution

JSONL Parser (src/lib/claude-session-parser.ts)

• Parses Claude Code session files from ~/.claude/projects/<encoded-project-path>/<session-uuid>.jsonl
• Handles all JSONL entry types: queue-operation, user, assistant
• Extracts structured content blocks (text, tool_use, tool_result)
• Uses cwd field from JSONL entries as authoritative working directory (encoded folder names are lossy for paths containing hyphens)
• File size guard (50MB max) to prevent memory issues with very large sessions
• Gracefully handles malformed JSONL lines

REST API

• GET /api/claude-sessions — Lists all available CLI sessions with metadata (project name, git branch, message counts, timestamps, file size)
• POST /api/claude-sessions/import — Imports a session into CodePilot database
  • Binds sdk_session_id so imported conversations can be resumed via the Claude Agent SDK
  • Duplicate import protection: returns 409 with existingSessionId if already imported
  • Stores messages using CodePilot's existing convention (plain text for text-only, structured JSON for tool calls)

UI (src/components/layout/ImportSessionDialog.tsx)

• "Import CLI Session" button added to the sidebar (ChatListPanel)
• Dialog shows all CLI sessions with:
  • Project name and git branch badge
  • First message preview
  • Message count, relative time, file size
  • Search/filter by project, message content, or branch
• One-click import with loading state
• On duplicate import (409), navigates to the existing session instead of showing an error

How It Works

1. User clicks "Import CLI Session" in the sidebar
2. Dialog scans ~/.claude/projects/ and displays available sessions
3. User clicks "Import" on a session
4. Backend parses the JSONL file, creates a CodePilot session, imports all messages, and binds the SDK session ID
5. User is navigated to the imported session and can continue the conversation

Testing

• 17 new unit tests covering:
  • Path decoding (decodeProjectPath)
  • Session discovery and listing (listClaudeSessions)
  • Full session parsing with text, tool_use, and tool_result blocks
  • Multi-turn conversations
  • Empty/malformed content handling
  • Preview truncation
  • Session info extraction
• All 38 tests pass (17 new + 21 existing)
• TypeScript compiles with zero errors

Files Changed

File	Change
src/lib/claude-session-parser.ts	New — JSONL parser core
src/app/api/claude-sessions/route.ts	New — List API
src/app/api/claude-sessions/import/route.ts	New — Import API with dedup
src/components/layout/ImportSessionDialog.tsx	New — Browse & import dialog
src/components/layout/ChatListPanel.tsx	Modified — Sidebar button
src/__tests__/unit/claude-session-parser.test.ts	New — 17 unit tests

Known Limitations

• listClaudeSessions reads all JSONL files on each call; users with hundreds of CLI sessions may see a brief delay when opening the dialog (rare in practice, and only triggered on dialog open)
• Encoded project folder names containing hyphens are ambiguous (e.g., -root-my-project could decode to /root/my-project or /root/my/project), but this is mitigated by using the cwd field from JSONL entries as the authoritative path