Codex SwitchBridge 0.3.1

What's new\n\n- Replaced the generic lightning icon with the S-Bridge identity.\n- Added a self-contained 256 px color master for Marketplace use.\n- Added a matching currentColor icon for the VS Code Activity Bar.\n- Added release tests for complete PNG identity and dimensions, SVG dependency safety, brand colors, and monochrome paint values.\n\nThis is a logo-only VS Code extension update. Switching, shared history, token usage, Core, and CLI behavior are unchanged.\n\n## Verification\n\n- Core tests: 101 passed\n- VS Code tests: 319 passed\n- Migration tests: 11 passed\n- CLI suite: passed\n- Dependency audit: 0 vulnerabilities\n- VSIX archive integrity and contents verified\n- Installed locally as baoshichao001-dev.codex-switchbridge@0.3.1