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/36b2834012d1cdc00773719f54bde65c57a0215fc52206054cf15bc5d4620cfb.json

@@ -0,0 +1 @@
+{"issues": [{"issue_id": "CON-001", "source_stage": "qaqc", "category": "missing_sheet", "severity": "critical", "confidence": "high", "location": "Entire Project", "disciplines": ["Structural", "Architectural", "Mechanical", "Electrical"], "sheets": ["M03.01", "E05.02", "A25.01"], "description": "The drawing set is entirely missing the Structural discipline (S-series sheets). Structural drawings are required to specify support for new rooftop units (RTUs), suspended transformers, framing for roof openings, and requirements for any slab penetrations. Multiple notes on Architectural, Mechanical and Electrical sheets refer to coordination with a structural engineer, but no drawings are provided.", "evidence": [{"discipline": "System", "sheet": "sheet_index", "source_text": "No sheets with the 'S' discipline prefix are present in the sheet index.", "asserted_value": "Missing Structural Drawings"}, {"discipline": "Electrical", "sheet": "E05.02", "source_text": "VERIFY SUPPORT SIZING AND DESIGNED WITH PROJECT STRUCTURAL ENGINEER PRIOR TO ASSEMBLY.", "asserted_value": "Reference to project structural engineer"}, {"discipline": "Mechanical", "sheet": "M03.01", "source_text": "ANGLE IRON FRAME ALL AROUND ROOF OPENING RE: STRUCTURAL.", "asserted_value": "Reference to structural drawings"}], "recommended_resolution": "Provide a complete set of structural drawings, including foundation plans, framing plans, and all necessary details for the new scope of work. Ensure MEP and Architectural drawings are coordinated with the new structural information.", "code_reference": null}, {"issue_id": "CON-002", "source_stage": "qaqc", "category": "missing_sheet", "severity": "critical", "confidence": "high", "location": "Entire Project", "disciplines": ["Architectural", "Mechanical", "Electrical", "Plumbing"], "sheets": [], "description": "Critical architectural plans appear to be missing from the set, corresponding to pages 14 and 15 where file extraction failed. These are expected to be the primary Architectural Dimension/Construction Plan and the Reflected Ceiling Plan (RCP). Without a dimensioned plan, construction layout is impossible. Without an RCP, coordination of lighting, HVAC diffusers, and sprinkler heads is impossible and ceiling heights are undefined.", "evidence": [{"discipline": "Architectural", "sheet": "page-14", "source_text": "Page 14 (extraction failed)", "asserted_value": "Expected to be the Dimension/Construction Plan"}, {"discipline": "Architectural", "sheet": "page-15", "source_text": "Page 15 (extraction failed)", "asserted_value": "Expected to be the Reflected Ceiling Plan"}], "recommended_resolution": "Provide the missing Architectural Dimension Plan and Reflected Ceiling Plan. Ensure all disciplines are coordinated with these new sheets.", "code_reference": null}, {"issue_id": "CON-003", "source_stage": "qaqc", "category": "missing_sheet", "severity": "critical", "confidence": "high", "location": "Entire Project", "disciplines": ["Mechanical", "Architectural"], "sheets": [], "description": "The Mechanical HVAC floor plan, expected as M02.01, is missing from the set, corresponding to page 22 where extraction failed. The sheet index jumps from Mechanical notes (M01.01) to the Mechanical Roof Plan (M02.02). Without the floor plan showing ductwork layout, diffuser locations, and thermostat locations, the HVAC system cannot be bid, permitted, or constructed.", "evidence": [{"discipline": "Mechanical", "sheet": "page-22", "source_text": "Page 22 (extraction failed)", "asserted_value": "Expected to be the Mechanical Floor Plan"}], "recommended_resolution": "Provide the missing Mechanical Floor Plan M02.01 and ensure it is coordinated with the architectural RCP and lighting plan.", "code_reference": null}, {"issue_id": "CON-004", "source_stage": "code", "category": "building_code", "severity": "critical", "confidence": "high", "location": "Project Wide", "disciplines": ["General", "Electrical", "Architectural", "Plumbing"], "sheets": ["E01.01", "G21.01", "A23.01"], "description": "Various drawings cite conflicting, and in some cases outdated, building, electrical, and energy codes. For example, G21.01 cites the 2018 IBC and 2014 NEC, while E01.01 cites the 2023 NEC and 2021 IBC, and other architectural and plumbing sheets cite 2021 codes. The project's adopted codes for the jurisdiction are reportedly the 2015/2017 editions. This fundamental discrepancy, identified across conflict, code, and QAQC reviews, must be resolved to establish a single, correct basis of design for permitting and construction.", "evidence": [{"discipline": "Electrical", "sheet": "E01.01", "source_text": "CONTRACTOR SHALL CONFORM TO ALL LOCAL, STATE, AND APPLICABLE CODES, 2023 NEC, 2021 IBC, 2021 IECC, NFPA, ETC.", "asserted_value": "2023 NEC, 2021 IBC, 2021 IECC"}, {"discipline": "General", "sheet": "G21.01", "source_text": "2018 INTERNATIONAL BUILDING CODE (IBC) CH. 2-10 WITH HARRIS COUNTY AMENDMENTS", "asserted_value": "2018 IBC"}, {Line truncated