v0.3.0a2

Alpha 2 on the v0.3 line. Closes the rule-editor bare-form-elements
debt called out in v0.3.0a1's release notes. No user-visible feature
changes — the rule editor looks slightly more polished (HA-native
field styling instead of bare-input fallback) but every existing rule
edits and saves the same way.

What's new

• Rule editor migrated to HA-native form elements. Every text /
  number input that drove the rule form now renders as ha-input
  (HA's current input, which replaced ha-textfield on 2026-04-01).
  The Mode dropdown and threshold-comparator dropdown both render as
  ha-selector with { select: { ..., mode: 'dropdown' } } config.
  The "+ Add entry" / "+ Add state" / "+ Add pattern" action buttons
  render as ha-button variant="neutral". Bare HTML survives only in
  the cases the new docs/ha-elements-guide.md decision tree
  endorses: the <input type="color"> swatch (no first-class HA
  color element), the per-rule and whole-config <textarea> YAML
  editors (ha-code-editor is overkill), and icon-button-style
  affordances (<button class="btn-icon">×</button> row delete,
  <button class="text-toggle"> code-editor toggle,
  <button class="action-error-dismiss">). Each carries an inline
  comment naming the guide.
• Drag-to-reorder thresholds. The per-row ↑ / ↓ buttons in
  threshold rules are replaced with a single drag handle on the
  left of each row, using HA's ha-sortable (the same wrapper
  HA's automation, dashboard, and area editors use). Six-dot
  mdi:drag glyph, grab/grabbing cursor, drop-anywhere
  reordering. The threshold-row layout is now a 2-column grid
  (handle column + indented content column) so the per-row
  fields stay aligned regardless of how many lines they wrap to.
• docs/ha-elements-guide.md (new) — internal/contributor
  reference for which ha-* elements to use, when bare HTML is OK,
  defensive patterns for lazy-load timing, and HA design tokens.
  Adapted from the sibling reference in weather-radar-card; the
  two docs are kept in sync.
• Playwright e2e smoke tests for the rule editor. Five specs
  covering the silent zero-height failure mode the lazy-load guide
  warns about (if an ha-* element didn't register, the rendered
  box collapses to zero — no console error). Runs against the
  docker testbed, sub-second per spec after auth is cached. See
  frontend/test-e2e/README.md for the setup workflow.

Internals

• 112 pytest + 85 Web Test Runner + 5 Playwright e2e + typecheck
  green; bundle drift clean.
• frontend/src/panel/rule-editor.ts: ~22 element conversions plus
  the connectedCallback whenDefined defensive list extended to
  cover ha-input, ha-button, ha-switch alongside the existing
  ha-icon-picker and ha-selector.
• AGENTS.md Code conventions section refreshed to point at the
  new guide.
• INTEGRATION_VERSION + manifest + frontend/package versions bumped
  to 0.3.0a2.

Upgrade

Drop-in from v0.3.0a1 — no behavior change, no schema migration.

Full Changelog: v0.3.0a1...v0.3.0a2