redesign web UI with verdict header, CSS lineage spine, and expandable findings

[gavxm]

• replace ReactFlow graph with a CSS vertical spine - drops @xyflow/react (~120KB), renders lineage as gutter dots + connector segments + node cards with tags and gated lock icons.
• add verdict header between topbar and panels - trust status (untrusted/caution/clean), natural language summary generated from findings, issue/source/timestamp stats, re-scan button on snapshots.
• rewrite finding cards as collapsible with severity bar, chevron, expanded detail, implicated evidence chips (clickable to jump to tab+field), and recommendation block.
• add severity filter pills to findings panel with grouped display.
• add field flag indicators (! chips) on evidence rows referenced by findings, with severity-colored values.
• add files list in declared tab with danger detection for pickle/executable extensions.
• add config.json syntax view fetched from HuggingFace with highlighted lines for flagged fields.
• add reverse highlighting - clicking a lineage node highlights related findings.
• add pulse animation on field highlights, re-triggerable via pulseKey.
• add responsive stacked view for narrow screens (verdict + findings only).
• add permalink URL length warning in export modal.
• extract LogoMark to shared component.
• remove module-level side effects from context provider.
• deduplicate highlight resolution into shared resolveHighlights helper.
• add AbortController to cancel stale HF search requests.