Dots Desktop 2.2.1 — One conversation, optional project panel

Each Dot now has one Conversation tab. Its project is an optional panel rather than a second conversation tab.

• Removed the universal Build tab. Open or close Project in the Conversation header, or open project files with the composer's folder button.
• Project panels start closed and belong to each Dot separately. Opening a project for one Dot does not change other Dots. Closing it preserves the conversation, draft, and referenced files.
• Fixed duplicate React keys for the conversation and project panels. Switching Dots no longer leaves an old conversation/composer on screen.
• Keeps all 2.2.0 coding features: code inspection, changed files, interactive static previews, local dev-server connections, actual command output, coding actions, and implementation/check/repair guidance.

Validation: TypeScript and production build passed. The packaged Windows app passed 21 end-to-end coding/navigation checks, including one Conversation tab, no separate Build tab, optional panels per Dot, one composer after Dot switching, draft/reference preservation, real file tools, failed-check repair, interactive previews, local dev-server embedding, isolation, and narrow layouts.

Windows x64 installer and portable app are included with SHA-256 checksums. Existing Dots, accessories, provider credentials, and workspaces are preserved.