test(writing): unit tests for prompt-builder + reference-resolver

64 new tests across two pure-logic surfaces — no Dexie / network /
component setup, runs in <150ms. Plus the LOCAL TIER PATCH revert
that's been waiting for the release window.

prompt-builder.test.ts (39 tests):
- buildDraftPrompt: ghostwriter system + topic/length/kind plumbing,
  optional audience/tone/extra-instructions, preset style injection,
  resolved-references rendering with singular/plural Quelle wording
  and proper bookend markers.
- All five selection prompts (shorten 50–60% / expand 150–180% / tone
  with target / rewrite with instruction / translate with target lang).
- buildTitleSuggestionPrompt: 4–8-word ask, no quotes, no period, no
  prefix; with/without excerpt block.
- cleanSuggestedTitle: now iterative-until-stable so combined artefacts
  ("Titel: \"Hello World\".") collapse in one call. Quote variants
  (straight, curly, German „, French «, single ‚) all stripped via
  asymmetric open/close sets.
- estimateMaxTokens: clamping to [256, 8000], words/chars/minutes
  conversions, fallback when targetLength is null.

reference-resolver.test.ts (25 tests):
- Per-kind shaping for article (siteName-prefix, content/excerpt
  fallback, truncation marker), note (untitled fallback), library
  (book metadata in the label), url (no fetch), kontext (singleton
  via scopedForModule, deletedAt skip), goal (plaintext, no decrypt
  call asserted), me-image (label + tags descriptor, kind fallback).
- Aggregate-budget enforcement in resolveReferences: drops nulls,
  stops adding once MAX_TOTAL_REFERENCE_CHARS is exceeded, but always
  keeps the first ref even if it alone busts the cap (so a single
  large reference doesn't silently produce zero output).

Side-fix: resolver uses `||` for the article content/excerpt fallback
so empty-string content (extraction failures) falls through to the
excerpt — `??` was passing empty strings as valid.

LOCAL TIER PATCH revert: requiredTier flips from 'guest' to 'beta'
in shared-branding/mana-apps.ts. Writing now gates correctly on
release; the comment marker is removed.

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

packages/shared-branding/src/mana-apps.ts

@@ -1086,7 +1086,7 @@ export const MANA_APPS: ManaApp[] = [
 		color: '#0ea5e9',
 		comingSoon: false,
 		status: 'development',
-		requiredTier: 'guest', // LOCAL TIER PATCH — revert to 'beta' before release
+		requiredTier: 'beta',
 	},
 	{
 		id: 'broadcast',