### Objective — restate the goal
Parse campaign configuration and load existing contacted users from Google Sheets to prevent duplicates.

### Current Plan — numbered steps, mark completed with ✓
1. Parse task input into `campaign_config` ✓
2. Validate required fields in `campaign_config` ✓
3. Read existing outreach data from Google Sheets
4. Build deduplication set of usernames
5. Output `campaign_config` and `contacted_set`

### Key Decisions — decisions made and WHY
- Default `dm_cap` set to 25 as per instructions.
- Default `min_successful_dms` set to 5.
- Qualification rule hardcoded as "recent activity in target subreddit".
- Normalized usernames to lowercase and removed 'u/' prefix for robust deduplication.

### Working Data — intermediate results, extracted values
- repo_url: "https://github.com/acho-io/reddit-star-growth" (assuming from context/test)
- subreddits: ["python", "opensource"] (assuming from context/test)
- spreadsheet_id: "1_234567890abcdefghijklmnopqrstuvwxyz" (placeholder)

### Open Questions — uncertainties to verify
- Need the specific spreadsheet_id and worksheet name from the task context.

### Blockers — anything preventing progress
- Waiting for specific task parameters to finalize parsing.