8-cut/docs/plans/2026-04-19-scan-history-negatives-implementation.md

Scan History & Hard Negative Management — Implementation Log

All tasks complete. See the design doc for the final specification.

Branch: feat/training-ui

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Task 1: Fix ghost folder bug in get_export_folders -- DONE

Commit: 2614a76 fix: get_export_folders respects scan_export filter

• core/db.py — get_export_folders(profile, include_scan_exports=False): filters scan_export = 0 by default
• core/db.py — get_training_stats(): passes include_scan_exports through, filters out 0-clip folders
• tests/test_db.py — test_export_folders_excludes_scan_exports

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Task 2: Scan result history — schema and DB methods -- DONE

Commit: 4fb2ae1 feat: scan result history — keep N versions per (file, model)

• core/db.py — added scan_timestamp TEXT NOT NULL DEFAULT '' column with migration
• core/db.py — save_scan_results(): versioned insert with microsecond-precision timestamp (%Y%m%d_%H%M%S_%f), auto-prunes beyond max_versions=5
• core/db.py — get_scan_versions(): returns [{timestamp, count, max_score}, ...] newest first
• core/db.py — get_scan_results(scan_timestamp=None): INNER JOIN subquery with MAX(scan_timestamp) for latest-by-default
• tests/test_db.py — test_scan_result_history

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Task 3: Scan history UI — version selector in ScanResultsPanel -- DONE

Commit: 8ed9fbf feat: scan version selector in results panel

• main.py — _add_tab(): wraps table in container QWidget with version QComboBox (hidden when ≤ 1 version)
• main.py — _current_table() / _tab_table(idx): unwrap container to get QTableWidget
• main.py — _populate_version_combos(): queries get_scan_versions(), formats labels with datetime.strptime + try/except fallback
• main.py — _on_version_changed(): reloads table from specific version, clears undo stack, emits regions_edited
• main.py — current_model_name(): extracts model name from tab text

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Task 4: Hard negatives — schema and training toggle -- DONE

Commit: edc5784 feat: hard negative source_model tracking, training toggle

• core/db.py — added source_model TEXT NOT NULL DEFAULT '' column to hard_negatives with migration
• core/db.py — add_hard_negatives(source_model=""): stores originating model
• core/db.py — get_hard_negatives(profile): returns full rows as list of dicts
• core/db.py — delete_hard_negatives_by_ids(ids): bulk delete by row IDs
• core/db.py — get_training_data(use_hard_negatives=True): conditionally skips hard negatives query
• main.py — TrainDialog: "Use hard negatives" checkbox + "Manage..." button in HBox layout
• main.py — _on_scan_negatives(): passes source_model=self._scan_panel.current_model_name()
• tests/test_db.py — test_hard_negatives_source_model, test_training_data_skips_hard_negatives, test_delete_hard_negatives_by_ids

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Task 5: Hard negatives management dialog -- DONE

Commit: e6db83f feat: hard negatives management dialog with filter and bulk delete

• main.py — HardNegativesDialog: table with File/Time/Source Model/hidden ID columns, model filter combo, delete selected, filter-aware clear all, close button
• Filter-aware "Clear All": respects active model filter, shows appropriate confirmation message

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Task 6: Code review fixes -- DONE

Commit: 5d45b8d fix: timestamp collision, undo stack invalidation, label parsing, filter-aware clear

Four issues found during code review:

1. Timestamp collision — second-precision timestamps could merge versions on sub-second calls. Fixed with microsecond precision %f
2. Undo stack invalidation — switching scan versions left stale undo entries. Fixed by clearing undo stack in _on_version_changed()
3. Timestamp label fragile parsing — hard-coded string slicing. Fixed with datetime.strptime + try/except fallback
4. Clear All ignoring filter — deleted all negatives regardless of model filter. Fixed to respect active filter

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Runtime fixes (discovered during manual testing)

Commit	Fix
a3c657c	Install torchvision from CUDA wheel index (was pulling CPU build from PyPI)
3c3b1d7	Remove "skip if torch exists" guard in Windows setup so re-runs fix broken envs
fd043f4	Pin transformers>=4.30,<5.0 — EAT remote model code incompatible with transformers 5.x
7d6fee9	Copy read-only numpy array before torch.from_numpy() in EAT preprocessing
bd345ab	Connect tab_changed to _on_scan_regions_edited so timeline refreshes on tab switch
d8b3972	Add --extra-index-url to pip install -r requirements.txt in both setup scripts

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Test results

All 68 tests pass (5 new DB tests + 63 existing).