feat: add qBraid branding system for white-labeling as CodeQ

[Kenny-Heitritter]

Summary

Adds a configuration-driven branding system to white-label opencode as CodeQ for qBraid.

Features

• Custom branding: CLI/TUI logo shows "code q" with purple Q
• Binary rename: opencode → codeq
• Env var prefix: OPENCODE_* → CODEQ_*
• Data directory: ~/.local/share/opencode/ → ~/.local/share/codeq/
• Custom models: Removes Zen, uses only qBraid, Anthropic, OpenAI providers

Files Added

branding/
├── apply.ts              # Branding script
├── schema.ts             # Configuration schema
├── README.md             # Documentation
└── qbraid/
    ├── brand.json        # qBraid/CodeQ config
    ├── models.json       # Custom model definitions
    └── generate-models.ts # Helper script

Usage

# Preview changes
bun branding/apply.ts qbraid --dry-run

# Apply branding
bun branding/apply.ts qbraid

# Build
cd packages/opencode && bun run build

# Test
./dist/codeq-darwin-arm64/bin/codeq --help

Design

• Pattern-based replacements that survive upstream updates
• Safe testing via git worktrees
• Extensible for other brands

[github-actions]

Thanks for your contribution!

This PR doesn't have a linked issue. All PRs must reference an existing issue.

Please:

1. Open an issue describing the bug/feature (if one doesn't exist)
2. Add Fixes #<number> or Closes #<number> to this PR description

See CONTRIBUTING.md for details.

[Kenny-Heitritter]