Initial commit: Conflict Checker

Cross-discipline design-contradiction checker for construction drawing
sets. Standalone tool broken out from Iron_Bid; a pipeline stage may
later fold back into Iron_Bid.

Pipeline: PDF->images -> per-sheet assertion extraction -> deterministic
clustering by location -> per-cluster reasoning -> report.
Includes CLI (cli/run_check.py) and web UI (backend/main.py).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

backend/.llm_cache/d2e21880bc98c83f8ded0b4eb8169706944fb52cd37254891c169dcca4271c99.json

@@ -0,0 +1 @@
+{"issues": [{"issue_id": "QAQC-001", "source_stage": "qaqc", "category": "missing_sheet", "severity": "critical", "confidence": "high", "location": "Drawing Set", "disciplines": ["Architectural", "Mechanical"], "sheets": ["G11.01"], "description": "Critical architectural and mechanical plan sheets are missing from the drawing set. The sheet index indicates pages 14, 15, and 22 failed extraction. Based on standard set organization, these are likely the Architectural Dimension/Construction Plan, the Architectural Reflected Ceiling Plan, and the Mechanical HVAC Plan. The drawing set is incomplete and cannot be bid, permitted, or built without these essential plans.", "evidence": [{"discipline": "System", "sheet": "sheet_index", "source_text": "Page 14 (extraction failed), Architectural, floor_plan", "asserted_value": "Missing Architectural Construction/Dimension Plan"}, {"discipline": "System", "sheet": "sheet_index", "source_text": "Page 15 (extraction failed), Architectural, reflected_ceiling_plan", "asserted_value": "Missing Architectural Reflected Ceiling Plan"}, {"discipline": "System", "sheet": "sheet_index", "source_text": "Page 22 (extraction failed), Mechanical, mep_plan", "asserted_value": "Missing Mechanical Floor Plan"}], "recommended_resolution": "Incorporate the missing plan sheets (A-Dimension Plan, A-Reflected Ceiling Plan, M-HVAC Plan) into the drawing set and update the sheet index.", "code_reference": null}, {"issue_id": "QAQC-002", "source_stage": "qaqc", "category": "missing_sheet", "severity": "critical", "confidence": "high", "location": "Drawing Set", "disciplines": ["Structural", "Architectural", "Mechanical", "Electrical"], "sheets": ["G01.01", "A25.01", "M03.01", "E05.02"], "description": "The drawing set has no Structural discipline sheets (S-series). This is a critical omission, as new rooftop units (RTUs) are specified, which impose new loads on the existing roof structure. Notes on Mechanical, Electrical and Architectural sheets explicitly require coordination with a structural engineer, yet no structural engineer is listed on the cover sheet (G01.01) and no structural drawings are provided to detail the required support or verify the capacity of the existing structure.", "evidence": [{"discipline": "System", "sheet": "sheet_index", "source_text": "Missing Expected Sheet: Structural Discipline", "asserted_value": "No S-sheets are present"}, {"discipline": "Mechanical", "sheet": "M03.01", "source_text": "ANGLE IRON FRAME ALL AROUND ROOF OPENING RE: STRUCTURAL.", "asserted_value": "Reference to Structural"}, {"discipline": "Electrical", "sheet": "E05.02", "source_text": "VERIFY SUPPORT SIZING AND DESIGNED WITH PROJECT STRUCTURAL ENGINEER PRIOR TO ASSEMBLY.", "asserted_value": "Requires verification with Structural Engineer"}, {"discipline": "Architectural", "sheet": "A23.01", "source_text": "ALL LOCATIONS OF CORE DRILLING OF THE FLOOR SLAB FOR INSTALLATION OF UTILITIES TO BE COORDINATED WITH LANDLORD'S STRUCTURAL ENGINEER BEFORE PERFORMING THE WORK", "asserted_value": "Requires coordination with Structural Engineer"}], "recommended_resolution": "Engage a structural engineer to review the existing structure, design support for new equipment, and produce the necessary structural drawings (S-series). Add the structural engineer to the consultant list on the cover sheet.", "code_reference": null}, {"issue_id": "QAQC-003", "source_stage": "qaqc", "category": "missing_schedule", "severity": "critical", "confidence": "high", "location": "Drawing Set", "disciplines": ["Architectural"], "sheets": [], "description": "The drawing set lacks Door and Window Schedules. Doors are shown on plans but are not tagged. Without schedules, essential information such as door/window sizes, types, materials, hardware groups, and fire-ratings are completely undefined. This information is critical for cost estimating, procurement, and code compliance for permitting.", "evidence": [{"discipline": "Architectural", "sheet": "G11.01", "source_text": "Sheet Index", "asserted_value": "No Door Schedule or Window Schedule sheet is listed."}, {"discipline": "Architectural", "sheet": "A24.01", "source_text": "Architectural Floor Plan", "asserted_value": "Doors are graphically indicated but have no identifying tags."}], "recommended_resolution": "Create and add Door and Window Schedules to the drawing set. Add corresponding tags to all doors and windows on the floor plans.", "code_reference": null}, {"issue_id": "QAQC-004", "source_stage": "qaqc", "category": "missing_detail", "severity": "high", "confidence": "high", "location": "Architectural Drawings", "disciplines": ["Architectural"], "sheets": ["G31.05", "G21.01"], "description": "There are no wall type definitions or a partition legend in the drawing set. While specifications on G31.05 mention gypsum board and G11.03 mentions R-19 insulation for demising walls, there is no comprehensive drawing that defines the full assemblies (stud size/gauge, spacing, insulatiLine truncated