# 027 — Dashboards: remove manual save, autosave everything

## Summary

`Dashboards.tsx` currently has an explicit "Save dashboard" button
(`saveDashboard` called on click). The wishlist wants dashboards to always
autosave — no explicit save step, matching how settings/profile changes already
persist immediately elsewhere in the app.

## Scope

- Remove the "Save dashboard" button and the `saving`/dirty-draft gating around
  it in `Dashboards.tsx`.
- Persist panel/name edits automatically: debounce edits (e.g. text field
  keystrokes) so autosave doesn't fire on every keystroke, but don't require any
  user action to commit a change.
- Cover all mutations that currently route through the save button: panel
  add/remove/edit (title, PromQL, chart type), dashboard rename.
- Surface save failures unobtrusively (e.g. a small inline status/error near the
  dashboard, not a blocking dialog) since there's no longer a discrete "Save"
  click to attach an error to.

## Acceptance criteria

- Editing a panel's title, query, or chart type persists without clicking
  anything, verified by reloading the page and seeing the change retained.
- Rapid typing in a text field doesn't spam the save endpoint on every keystroke.
- A failed autosave (e.g. simulated API error) surfaces to the user without
  losing the in-progress edit.

## Depends on

None — modifies the existing `Dashboards.tsx` save path.