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Excluded from rename: .claude/, devlog/, manascore/ (historical content),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>

docs/URL_SCHEMA.md

@@ -34,7 +34,7 @@ This document defines the URL schema for all mana.how subdomains.
 | Service | URL | Description |
 |---------|-----|-------------|
 | **Main Dashboard** | mana.how | Main landing/dashboard |
-| **Auth Service** | auth.mana.how | Central authentication (mana-core-auth) |
+| **Auth Service** | auth.mana.how | Central authentication (mana-auth) |
 | **API Gateway** | api.mana.how | Unified API gateway |
 | **Media Service** | media.mana.how | Image/video processing |
 | **LLM Service** | llm.mana.how | LLM abstraction layer |
@@ -63,7 +63,7 @@ For web analytics, the following apps are tracked in Umami:
 
 | Umami Website ID | Display Name | Domain |
 |------------------|--------------|--------|
-| `manacore-webapp` | Dashboard | mana.how |
+| `mana-webapp` | Dashboard | mana.how |
 | `chat-webapp` | Chat | chat.mana.how |
 | `todo-webapp` | Todo | todo.mana.how |
 | `calendar-webapp` | Calendar | calendar.mana.how |