v0.0.2: WYSIWYG settings + coloured weather icons

[eldios]

Summary

• WYSIWYG settings. Saving the config page now applies every value it shows, not only the ones you touched. Previously the page sent only the keys that differed from a phone-side baseline (localStorage), which is not authoritative and drifts from the watch (reinstall, a different phone, or JS defaults that never matched the firmware). A value shown in the page but left untouched was silently never applied — e.g. a complication reading "Location" in the settings yet staying "Date" on the watch. Every non-translation setting is now always sent (the C inbox handler already applies only the keys present, so this stays idempotent). Translation strings stay delta-only to fit the watch's 1280-byte inbox; the language picker resends them when it changes them.
• Coloured weather icons on colour watches (basalt, emery): the condition glyph is tinted by meaning — sun amber, rain/snow blue, lightning amber, moon pale yellow — while the temperature keeps the theme colour. Black-and-white watches (diorite, flint) are unchanged.
• Weather → Icon style selector: Default (colour where the platform supports it, B&W otherwise, and it follows the Mono theme's monochrome look), Colour (force the tinted icons, overriding the Mono theme), or Black & White (force the classic monochrome glyph on colour watches too).
• Config defaults aligned to firmware (the above-calendar Week and AM/PM slots, low-battery threshold), so a fresh install shows the watch's real out-of-box state before the first save.

Compatibility

adv_settings.weather_icons is appended at the end of the persisted struct, so existing saved blobs keep the Default value via the static initializer — no reset, fully backward compatible (persist_read_data tolerates a shorter stored blob).

Test plan

Verified inside nix develop:

• Host unit suite: 18/18 passing (tools/test.sh).
• pebble build completes for basalt, diorite, emery, flint.
• strict-check clean under the cloud's -Werror flag set on all four platforms (zero warnings) — both PBL_COLOR and PBL_BW paths.
• Config JS logic with node: the "ghost setting" scenario is fixed; payload stays under the 1280-byte inbox (~835 B common case, ~831 B AppMessage on a full language switch); the new Icon style field renders with Default selected and is included in the always-send set.
• Not verified visually on the emulator (screenshots to be captured separately).