…gaps, test markers

Three workstreams implemented in parallel:

1. Security hardening (SSC-3 + SSC-6):
   - YAML document-size limit (10 MB) in generic and STPA adapters
   - Dashboard default bind to 127.0.0.1 (warns on 0.0.0.0)
   - 2 new unit tests for size limit enforcement

2. Dashboard filter/sort/pagination:
   - /artifacts: ?types=, ?q=, ?sort=, ?dir=, ?per_page=, ?page=
   - Filter bar with search input, type dropdown, per-page selector
   - Sortable column headers with direction arrows
   - Windowed pagination with prev/next/ellipsis
   - /stpa: filter bar with type checkboxes and text search
   - All href values match hx-get (no href="#")

3. V-model traceability:
   - FEAT-016 now satisfies REQ-003 (ASPICE V-model)
   - FEAT-014 now satisfies REQ-009 (test results evidence)
   - DD-039 created for REQ-022 (asset embedding rationale)
   - 324 `// rivet: verifies REQ-XXX` markers added across 22 source files

Validate: PASS 0 warnings. All tests pass.

Implements: FEAT-065
Satisfies: REQ-012

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>