# Verification Note: Phase 7.2 Coordinator (pdftract-3zhf)

## Work Completed

### 1. Unified Detection Entry Point
Added `TableDetector::detect(&PageContext) -> Vec<GridCandidate>` method that:
- Runs line-based detection first (m/l/S, re/S, re/f operators)
- Runs borderless detection second (x0 alignment heuristic)
- Combines results from both pipelines

### 2. All Child Beads Closed
- ✅ pdftract-88sk (7.2.1): Line-based table detection
- ✅ pdftract-3nwz (7.2.2): Borderless table detection
- ✅ pdftract-2oqh (7.2.3): Span-to-cell assignment
- ✅ pdftract-ilen (7.2.4): Header row detection
- ✅ pdftract-3c4i (7.2.5): Merged cell detection
- ✅ pdftract-5mph (7.2.6): Table JSON output schema integration

### 3. Critical Tests Pass

#### PASS: 5x3 Bordered Table
- Test: `test_detect_5x3_table`
- Location: `crates/pdftract-core/src/table/detector.rs:899`
- Result: All 15 cells extracted with correct row/column indices

#### PASS: Merged Header Cell (colspan=3)
- Test: `test_detect_merged_cells_colspan_3_critical_test`
- Location: `crates/pdftract-core/src/table/cell.rs:1707`
- Result: Header cell correctly detected with colspan=3

#### PASS: Borderless Table Detection
- Test: `test_detect_borderless_3x3_table_accepted`
- Location: `crates/pdftract-core/src/table/detector.rs:1040`
- Result: Borderless 3-column table detected via x0 alignment

#### PASS: Two-Page Table Continuation
- Test: `test_detect_two_page_tables_basic`
- Location: `crates/pdftract-core/src/table/output.rs:389`
- Result: Table continuation detected and flagged correctly

### 4. Schema Verification
- File: `docs/schema/v1.0/pdftract.schema.json`
- Table shape includes all required fields:
  - id, bbox, rows, header_rows
  - detection_method ("line_based" | "borderless")
  - continued, continued_from_prev
  - page_index

### 5. Documentation
- File: `docs/research/table-structure-reconstruction.md`
- Contains algorithm diagrams and explanations

## Test Results
```
cargo test --package pdftract-core --lib table
test result: ok. 122 passed; 0 failed; 0 ignored
```

## Files Modified
- `crates/pdftract-core/src/table/detector.rs`: Added `detect()` method
- `crates/pdftract-core/src/table/mod.rs`: Public API exports

## Commit
- Hash: `e995808`
- Message: `feat(pdftract-3zhf): add unified TableDetector::detect entry point`