docs(adr): rename ADR-012 — drop Lazar; update title + content + cross-refs

- Rename docs/decisions/adr-012-lazar-conformance.md → adr-012-feature-conventions.md
- Strip "Lazar", "Plan 8/9/10/11", "refactor-logs" refs from all ADRs,
  architecture docs, HTML explainers, and feature/core AGENTS.md files
- Update all incoming links in docs/, packages/*/AGENTS.md, HTML explainers

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

docs/architecture/di-explainer.html

@@ -641,7 +641,7 @@ footer .colophon {
   font-size: 10.5px; color: var(--ink-3); letter-spacing: 0.04em;
 }
 
-/* ─── §08 Instrumentation symbols (Plan 10) ──────────────────────── */
+/* ─── §08 Instrumentation symbols ──────────────────────────────── */
 
 .instrumentation-grid {
   display: grid;
@@ -1164,7 +1164,7 @@ footer .colophon {
   </div>
 </section>
 
-<!-- ─── 08 ─ INSTRUMENTATION SYMBOLS (Plan 10) ────────────────────────── -->
+<!-- ─── 08 ─ INSTRUMENTATION SYMBOLS ──────────────────────────────────── -->
 <section id="instrumentation">
   <div class="section-head">
     <div class="section-num">§ 08</div>
@@ -1245,7 +1245,7 @@ footer .colophon {
     <div>
       <h5>Decisions</h5>
       <a href="../decisions/adr-008-per-feature-di-containers.md">adr-008 · per-feature DI</a>
-      <a href="../decisions/adr-012-lazar-conformance.md">adr-012 · Lazar conformance</a>
+      <a href="../decisions/adr-012-feature-conventions.md">adr-012 · feature conventions</a>
       <a href="../decisions/adr-013-input-output-unification.md">adr-013 · I/O unification</a>
     </div>
     <div>