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Excluded from rename: .claude/, devlog/, manascore/ (historical content),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

README.md

@@ -1,12 +1,12 @@
-# Manacore Monorepo
+# Mana Monorepo
 
-Monorepo containing all Manacore projects — a self-hosted multi-app ecosystem with shared packages and unified tooling.
+Monorepo containing all Mana projects — a self-hosted multi-app ecosystem with shared packages and unified tooling.
 
 ## Projects
 
 | Project | Description | Apps |
 |---------|-------------|------|
-| **manacore** | Multi-app ecosystem platform | Expo mobile, SvelteKit web |
+| **mana** | Multi-app ecosystem platform | Expo mobile, SvelteKit web |
 | **chat** | AI chat application | NestJS backend, Expo mobile, SvelteKit web, Astro landing |
 | **todo** | Task management | NestJS backend, SvelteKit web, Astro landing |
 | **calendar** | Calendar & scheduling | NestJS backend, SvelteKit web, Astro landing |
@@ -62,7 +62,7 @@ See [CLAUDE.md](./CLAUDE.md) for comprehensive development documentation.
 ## Architecture
 
 ```
-manacore-monorepo/
+mana-monorepo/
 ├── apps/                    # Product applications
 ├── services/                # Microservices (auth, search, LLM, bots)
 ├── packages/                # Shared packages