docs(beads): etch project history into memory bank and finalize skill-bb

We completed the 'Deep Metadata Etch' today, transforming our Beads issues from simple trackers into a permanent narrative of our collaboration.

Triumphs:
- Exhaustively updated all epic and sub-task descriptions with technical implementation reports and 'Execution Tales'.
- Finalized the 'bb' agent CLI skill (bb.ps1), providing a reliable, path-safe interface for cross-agent communication.
- Published ADR-001 and RFC-001 to document our coordination protocols.
- Fixed the 'missing closed issues' bug across all pages by enforcing --all and --limit 0 in read-issues.ts.

Raw Honest Moment:
We realized our 'Memory Bank' was initially too shallow. We went back and re-wrote descriptions for over 15 beads to ensure that future AI agents (and human maintainers) understand not just *what* we built, but *why* we chose specific architectural trade-offs. This commit represents our commitment to documentation as a first-class citizen of engineering.

src/app/graph/page.tsx

@@ -25,6 +25,7 @@ export default async function GraphPage({ searchParams }: GraphPageProps) {
     mode: scope.mode,
     selected: scope.selected,
     scopeOptions: scope.options,
+    preferBd: true,
   });
   return (
     <DependencyGraphPage

src/app/page.tsx

@@ -23,6 +23,7 @@ export default async function Page({ searchParams }: PageProps) {
     mode: scope.mode,
     selected: scope.selected,
     scopeOptions: scope.options,
+    preferBd: true,
   });
   return (
     <KanbanPage