feat: add --json output flag to all commands (closes #1)

[chengfei-gh]

Feature for #1: Add --json output format

Implementation

Added --json flag to all commands (add, list, done) that outputs valid, parseable JSON.

JSON Output Format

// Success responses
{"status": "ok", "task": {"id": 1, "description": "Buy milk", "done": false}}
{"status": "ok", "tasks": [{...}, {...}]}

// Error responses
{"status": "error", "message": "No tasks found"}

Usage Examples

python task.py add "Buy milk" --json
# {"status": "ok", "task": {"id": 1, "description": "Buy milk", "done": false}}

python task.py list --json
# {"status": "ok", "tasks": [{"id": 1, "description": "Buy milk", "done": false}]}

python task.py done 1 --json
# {"status": "ok", "task": {"id": 1, "description": "Buy milk", "done": true}}

Changes

• task.py: Added --json flag to main parser and all subcommand parsers
• commands/add.py: JSON output with new task details
• commands/list.py: JSON output with all tasks array
• commands/done.py: JSON output with updated task or error

Acceptance Criteria

• All commands support --json flag
• JSON output is valid and parseable
• Backward compatible (default output unchanged)
• Consistent {status, ...} envelope format

Payment

Solana wallet: CZkLs4m55JBffoowGUtyfqb5GrymUVxgr9kMTrXKfbJV