Add multi-day history rings + fix HA editor dropdown components

[sxdjt]

Summary

• Multi-day history rings: any history/consumption layer can now render N concentric rings (one per day, max 7) by setting days: N. Outer ring = today, inner rings = progressively older days. Includes shared min/max scaling across the group, configurable opacity fade for older rings, and optional day labels.
• Editor dropdown fixes: replaced all deprecated ha-select / mwc-list-item patterns with ha-selector (select type), and replaced boolean ha-select fields with ha-switch. This resolves visual editor dropdowns that stopped working in recent HA versions.

Background

This reimplements PR #4 (multi-day rings). That PR was closed because the local development repo was accidentally deleted. This is a clean reimplementation against the current v1.0.8 Beta codebase.

Changes

dist/andy-stats-clock.js

Editor fixes

• ha-select / mwc-list-item replaced with ha-selector (select type) for: clock mode, layer type, value source, history day, color mode, center layer type, bottom layer type, day label format, day label position
• Boolean ha-select fields replaced with ha-switch for: show hour labels, show minute ticks, hands share center pivot, enable hour/minute/second hand, center show icon, bottom show icon

Multi-day rings

• New _getHistoryForDay(lc, hass, stateObj, dayOffset) - fetches and caches one day's hourly buckets per ring. Cache keys are scoped per entity + layer + day offset + segment count. TTL: 5 min for today, 10 min for past days. Includes forward/backward fill and future-hour nulling for today.
• _buildLayerData() rewritten to pre-expand layers with days > 1 into N entries before radius assignment, so each day-ring occupies its own concentric slot. A second pass shares min/max across the group for a consistent color scale.
• Segment rendering: multi-day fade applied per ring (opacity * max(0, 1 - dayIndex * fadeStep)); stats markers suppressed on non-today rings.
• New _renderDayLabel(cfg, layer) - SVG text label at ring midpoint in relative ("Today", "Yesterday", "2d ago") or date ("Jan 15") format.
• Editor: multi-day section added with controls for days count, fade, fade step, day labels, label format, label position. "History day" selector and "Keep values across midnight" are hidden automatically when days > 1.

CHANGELOG.md (new)

Documents both the editor fixes and the multi-day feature.

MULTI-DAY-RINGS.md (new)

Proposed documentation for the README - config reference table and YAML examples. The maintainer can copy the relevant sections directly into README.md.

New layer config keys

Key	Default	Description
days	1	Number of day rings (1-7). 1 = existing single-day behaviour unchanged.
day_fade	true	Fade opacity on older rings.
day_fade_step	0.25	Opacity reduction per day: base * max(0, 1 - dayIndex * step).
day_labels	false	Show text label on each ring.
day_label_format	relative	relative (Today / Yesterday / Nd ago) or date (Jan 15).
day_label_position	right	Clock position: right, left, top, bottom.
day_label_font_size	3	SVG font size.
day_label_color	rgba(255,255,255,0.7)	Label text color.