chore: complete ManaCore → Mana rename (docs, go modules, plists, images)

Final cleanup of references missed in previous rename commits:

- Dockerfiles: PUBLIC_MANA_CORE_AUTH_URL → PUBLIC_MANA_AUTH_URL
- Go modules: github.com/manacore/* → github.com/mana/* (7 go.mod files)
- launchd plists: com.manacore.* → com.mana.* (14 files renamed + content)
- Image assets: *_Manacore_AI_Credits* → *_Mana_AI_Credits* (11 files)
- .env.example files: ManaCore brand strings → Mana
- .prettierignore: stale apps/manacore/* paths → apps/mana/*
- Markdown docs (CLAUDE.md, /docs/*): mana-core-auth → mana-auth, etc.

Excluded from rename: .claude/, devlog/, manascore/ (historical content),
client testimonials, blueprints, npm package refs (@mana-core/*).

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

scripts/test-reporting/README.md

@@ -129,7 +129,7 @@ node format-metrics.js ./test-results/metrics.json
     "branches": { "total": 400, "covered": 340, "pct": 85 }
   },
   "suites": {
-    "mana-core-auth": { /* same structure */ },
+    "mana-auth": { /* same structure */ },
     "chat-backend": { /* same structure */ }
   }
 }
@@ -164,7 +164,7 @@ node format-metrics.js ./test-results/metrics.json
     "suite": "integration/auth-flow.spec.ts"
   },
   "suiteMetrics": {
-    "mana-core-auth": {
+    "mana-auth": {
       "tests": 120,
       "duration": 15000,
       "slowestTest": { /* ... */ }
@@ -187,8 +187,8 @@ To track additional metrics:
 
 ```bash
 # Create mock test results
-mkdir -p test-data/coverage-mana-core-auth
-echo '{"total":{"lines":{"total":100,"covered":85,"pct":85}}}' > test-data/coverage-mana-core-auth/coverage-summary.json
+mkdir -p test-data/coverage-mana-auth
+echo '{"total":{"lines":{"total":100,"covered":85,"pct":85}}}' > test-data/coverage-mana-auth/coverage-summary.json
 
 # Run aggregation
 node aggregate-coverage.js test-data aggregated-output