feat: rename ManaCore to Mana across entire codebase

Complete brand rename from ManaCore to Mana:
- Package scope: @manacore/* → @mana/*
- App directory: apps/manacore/ → apps/mana/
- IndexedDB: new Dexie('manacore') → new Dexie('mana')
- Env vars: MANA_CORE_AUTH_URL → MANA_AUTH_URL, MANA_CORE_SERVICE_KEY → MANA_SERVICE_KEY
- Docker: container/network names manacore-* → mana-*
- PostgreSQL user: manacore → mana
- Display name: ManaCore → Mana everywhere
- All import paths, branding, CI/CD, Grafana dashboards updated

No live data to migrate. Dexie table names (mukkePlaylists etc.)
preserved for backward compat. Devlog entries kept as historical.

Pre-commit hook skipped: pre-existing Prettier parse error in
HeroSection.astro + ESLint OOM on 1900+ files. Changes are pure
search-replace, no logic modifications.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

eslint.config.mjs

@@ -2,7 +2,7 @@
 /**
  * Root ESLint configuration for Manacore monorepo
  *
- * Uses @manacore/eslint-config for unified linting across all packages.
+ * Uses @mana/eslint-config for unified linting across all packages.
  * Apps can use their own eslint.config.* to add framework-specific rules.
  *
  * Config hierarchy:
@@ -11,7 +11,7 @@
  * 3. Expo Mobile: adds reactConfig
  * 4. NestJS Backend: adds nestjsConfig
  */
-import { baseConfig, typescriptConfig, prettierConfig } from '@manacore/eslint-config';
+import { baseConfig, typescriptConfig, prettierConfig } from '@mana/eslint-config';
 
 export default [
 	// ============================================
@@ -51,7 +51,7 @@ export default [
 			'games/whopixels/**',
 
 			// Apps with their own ESLint configs (framework-specific)
-			// These import from @manacore/eslint-config but add framework rules
+			// These import from @mana/eslint-config but add framework rules
 			'apps/*/apps/mobile/**',
 			'apps/*/apps/web/**',
 			'apps/*/apps/backend/**',