feat(app): revamp provider and workspace surfaces

[astyfx]

Summary

• Update Claude and Codex provider runtime integration, schemas, runtime options, and model defaults for the current sendbird/stave main branch.
• Remove the legacy Stave Auto, Muse, and Coliseum fan-out surfaces, docs, screenshots, helpers, and tests.
• Refresh workspace/task shell behavior, provider settings, prompt presets, command palette entries, and shared shadcn motion primitives inspired by transitions.dev.
• Reconcile the release workflow test with the current gh release upload flow after rebasing the work onto sendbird/stave main.

Verification

• git diff --cached --check
• bun run typecheck
• bun test
• bun run build
• bun run build:desktop

Note: bun run build completes with the existing Vite chunk-size warning for large renderer chunks.