feat: add spatial passenger shell v1

[FHoffarth]

Summary

• Spatial Passenger Shell v1: Built a mobile-first, luxury travel presentation shell (<ShipOverview />) for exploring verified ship layouts.
• Dual-Gate Admission Architecture: Implemented isAdmittedPassengerEntity() (frontend/src/ship-overview/adapter.ts) enforcing both canonical Lifecycle Admission (EvidenceCondition.SUPPORTED + HumanReviewState.APPROVED + PublishStatus.PUBLISH_ALLOWED) and Geometry Provenance Admission (DIRECT_SOURCE_GEOMETRY, TRANSFORMED_SOURCE_GEOMETRY, DERIVED_GEOMETRY).
• Deck 14 Canonical Verification Slice: Renders 243 source-derived cabin polygons and 1 derived vertical core region ("Vertical Core Area").
• Zero Hallucination / Scope Bounds:
  • 0 unadmitted venues leak into passenger UI (87 stored DRAFT/PUBLISH_BLOCKED venue statements are strictly excluded).
  • Decks without admitted geometry are omitted from the selector with a clean note: "More deck views are not available yet."
  • No synthetic, ungrounded, or unverified geometry is rendered as mapped truth.
  • No turn-by-turn routing, walking connectivity, step-free access, or "Nearby" recommendations are implied or calculated.
• Interactive SVG Deck Canvas: Supports pan, zoom, fit-to-deck, and entity selection with immutable source coordinate guarantees.
• Accessibility & Mobile-First Design: Semantic headings, accessible button labels, keyboard operable shapes, and responsive layout across 320px, 390px, 768px, and 1280px viewports.

Test & Validation Coverage

• Frontend Vitest Suite: 72/72 tests passing (including 16 comprehensive spatial lifecycle and boundary tests in frontend/src/ship-overview/ShipOverview.test.tsx).
• Frontend Production Build: Clean Vite production build with zero TypeScript errors.
• Backend Test Suite: 892/892 pytest tests passing across 72 test suites.
• Diff Hygiene: git diff --check is clean with zero whitespace issues.