OpenConstructionERP Files

### Added

• New Clash Detection module (/clash): intra-project geometric interference + clearance coordination over real GLB element geometry — exact OBB-SAT + Möller tri-tri narrow phase, discipline×discipline matrix, Navisworks/Solibri-grade review table, BCF export, one-click "Isolate in 3D".
• Clash: Navisworks-style category/type selection sets (Set A × Set B) as the primary search mode; collision results deep-link into the BIM viewer and frame the camera on the clash centroid.
• Clash: active-project context panel — model/element/run summary + working links to BIM 3D Viewer, element matcher and project overview.
• New Incoming Webhook Leads module (oe_webhook_leads): secure POST /incoming/{source} ingestion (API-key/HMAC/JWT, IP allow-list, rate limit), payload→lead mapping, audit log, Settings UI (#147).
• File manager: clicking a BIM model offers BIM 3D Viewer / CAD-BIM BI Explorer / Clash Detection navigation.

Fixed

• Multi-currency: foreign-currency positions now convert correctly in section subtotals (two places) and project totals; FX-correct CSV/Excel export with a frozen-rate appendix (#111).
• "Add partida" now inserts directly below the selected row instead of elsewhere (#139).
• AI Chat now renders the streamed answer (OpenRouter/OpenAI SSE) instead of staying blank while tokens are consumed (#138).
• BOQ supports up to 8 nested section/partida levels with recursive subtotals and a /v1/boq/limits/ contract (#136).
• Resources can carry a unique code with a reuse-or-create prompt and master→instance propagation (#133).
• Clash 3D: collisions now actually display (fixed GLB load-race, element highlight and camera target).
• File manager: BIM-model and sheet rows no longer report 0 bytes — size falls back to the real GLB artifact / parent-document share.
• Hardened JSON-column deserialization: a legacy/gap-fill scalar in a JSON column (e.g. activity = construction) no longer 500s every read of the affected row — fixed the "Failed to add position / Internal server error" and project-profile crashes via a tolerant engine json_deserializer.
• BOQ: deleting a sub-section that contains nested sub-sections now works — the editor delegates to the backend's recursive cascade instead of a flat child sweep that silently 409'd.
• Clash: the active-project panel's BIM 3D Viewer / Match / Project-overview buttons now navigate (were inert due to a button-inside-link); BIM target picks the first model with parsed geometry.

Changed