feat: edit agent settings in team drawer

[rogerchappel]

Summary

• Make the Team agent drawer the single edit surface for agent settings
• Inline the existing agent config fields and voice chooser under the drawer Settings tab
• Remove the old Team edit-agent modal path so users no longer bounce through two layers

Verification

• pnpm typecheck
• pnpm build
• git diff --check
• Browser smoke: local app booted and redirected to first-run auth; authenticated drawer interaction still needs a logged-in visual pass

Risk

Medium: changes the primary Team agent settings workflow, but keeps API calls and existing config field components intact.