feat(guard): active-content detector wired into the output gate (review MAJOR #1)

Close the EchoLeak wiring hole (CVE-2025-32711 class): markdown images/
links, reference definitions, autolinks, raw active HTML and data: URIs
now surface as report-only findings (active:*, OWASP LLM05) in
scan_output step 6, so screen_output and okf.import_bundle dispose of
them instead of admitting them with findings=[].

- new active_content.py: canonical home of the shared pattern table +
  scan_active_content; neutralize refactored to import it (mutating API
  and behavior unchanged, all neutralize tests pass as-is)
- images/links flagged only for absolute/protocol-relative URLs:
  relative in-bundle links are legitimate wiki/OKF mechanism (principle 5)
- evidence carries defanged URLs only (hxxps://evil[.]example)
- EchoLeak vectors planted in both showcases; detach proofs cover them
- README export list + checklist step 6, CLAUDE.md context line updated

Suite: 321 -> 341 passed. Core invariant intact (dependencies=[]).

CLAUDE.md

@@ -11,8 +11,9 @@ framework-agnostisk kode.
 Referanse-implementasjon: `claude-code-llm-wiki` Stage B (`tools/wiki_ingest/`).
 Lexikon-seed: `injection-patterns.mjs` fra `llm-security`-pluginen.
 
-Repoet er på **v0.1 (alpha)**: stdlib-kjernen er bygget og testet (10 moduler +
-topp-nivå wiring, showcase + korpus). Start med `docs/BRIEF.md` for design,
+Repoet er på **v0.2 (alpha)**: stdlib-kjernen er bygget og testet (12 moduler +
+topp-nivå wiring, showcase + korpus), inkl. OKF-adapter og aktivt-innhold-
+detektor (EchoLeak-klassen) i output-gaten. Start med `docs/BRIEF.md` for design,
 `README.md` for bruk, `docs/PLAN.md` for byggerekkefølgen.
 
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