## Summary
Add a labeling system for transactions that differs from categories in
that labels are ephemeral and created on-the-fly when assigned (no
pre-creation required). A transaction can have multiple labels
(many-to-many relationship), and labels can be used for filtering in the
transaction table and as actions in automation rules.
<img width="1372" height="484" alt="image"
src="https://github.com/user-attachments/assets/fd342b11-dafb-44ed-b818-578e1ea856e6"
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<img width="1373" height="613" alt="image"
src="https://github.com/user-attachments/assets/aa5cfb8b-50b7-4101-a872-54904924f234"
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<img width="1035" height="594" alt="image"
src="https://github.com/user-attachments/assets/ffa946b2-b01f-496b-8cb8-ab55ab5b79ed"
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## Changes
### Backend (Laravel)
- Add `labels` table with user_id, name, color, and soft deletes
- Add `label_transaction` pivot table for transaction-label many-to-many
- Add `automation_rule_labels` pivot table for automation rule-label
many-to-many
- Create Label model with relationships to User, Transaction, and
AutomationRule
- Add LabelController for CRUD operations (returns JSON for on-the-fly
creation)
- Add LabelSyncController for frontend sync
- Add LabelPolicy for authorization
- Update TransactionController to handle bulk label updates
- Update AutomationRuleController to handle label actions
- Add validation for label_ids in transactions and automation rules
### Frontend (React/TypeScript)
- Add Label type and color utilities
- Add labels table to IndexedDB (Dexie version 6)
- Create label-sync service with findOrCreate functionality
- Create LabelCombobox component with multi-select and create-on-type
- Add labels column to transactions table
- Add labels filter to transaction filters
- Add bulk label assignment in bulk actions bar
- Add labels action in create automation rule dialog
- Update rule engine to include labels in evaluation results
## Testing
- 11 feature tests for label CRUD
- 3 tests for label sync
- All 241 feature tests pass
## Screenshots
N/A - UI changes can be reviewed in browser