docs(adr): record Bun 1.4.3 verification results and decisions

Stable Bun 1.4.3 runs installs, the development server, standalone type
checks, the native test runner and a Bun.serve static server. Native
lint/fmt are canary-only, and Angular's server build needs Node loader
hooks Bun does not apply, so the spec now keeps ESLint/Prettier until a
stable release, builds Angular client-only behind a Bun static server,
converts line coverage from lcov, and replaces the heap cap with a
container memory limit.

Refs #289

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docs/adr/0009-bun-runtime-and-native-tooling.md

@@ -11,6 +11,14 @@ This deliberately accepts Bun-specific tooling and migration work while retainin
 Angular's standard compiler and build pipeline, including TypeScript 6 for
 Angular compilation alongside `bun check` for standalone TypeScript checking.
 
+Verification on stable Bun 1.4.3 narrowed this: ESLint and Prettier stay,
+run by Bun, until a stable release ships the native linter and formatter;
+Angular builds a client-only bundle, because its server build relies on Node
+loader hooks Bun does not apply, and a small `Bun.serve` server delivers it,
+giving up `@angular/ssr`; coverage is line-level, converted from lcov to the
+existing HTML and Cobertura reports; and the benchmark's heap cap becomes a
+container memory limit.
+
 Existing behavior, tests, lint rules, coverage reporting, and benchmark budgets
 must be preserved; incompatibilities must be fixed or reported as blockers before
 declaring completion, and a Node.js fallback does not meet the runtime requirement.