feat(dashboard): simplify Config and Volume mount controls#1499

Why

Config editing was buried under routine inventories and permanent mount forms. Files now lead the Config drawer, and mount management stays in Config and Volume resource drawers.

What changed

• Put Add at the top right and Edit directory and Unmount in trailing row menus in the resource drawers.
• Remove Config and Volume mount inventories and controls from Service settings, including their unused data subscription and component branches.
• Move file metadata into the existing file menu. Preserve input on refusal, keyboard focus, pending saves, and visible errors.

Scope

Covers dashboard presentation, mount forms, and the related guides. EnvironmentChangesReview retains Save, Publish, Deploy, and discard ownership. The Config Commits prototype is separate.

Blast Radius

Config mounts remain read-only. Volume writer restrictions, storage locking, staged removal, data-loss confirmation, Service replica caps, and the database missing-volume warning remain.

Verification

• cd dashboard && pnpm pr:check passed all 1,179 tests in 180 files, static checks, and app and worker builds.
• Seeded browser verification confirmed Service mount sections are absent and Config and Volume directory edits persist after reload.
• Independent source review passed. Earlier browser checks covered add, unmount, collision recovery, keyboard focus, and narrow layout. No fresh runtime deployment ran.

Current screenshot and reports are under /home/codex/outputs/configs-ui-implementation/. See screenshots/20-service-settings-no-mounts.png, service-removal.md, and remove-service-final-pr-check.log. The earlier video shows the prior Service layout.