Drop the OsmAnd-recolor map theme, add offline labels and a lighter palette nudge

Remove osmand-style.js (the per-layer color-patching approach) and its
docs entirely — back to the plain OpenFreeMap "liberty" style online,
and protomaps-themes-base's stock theme offline as the base.

Offline maps previously had no text labels at all: the
protomaps-themes-base layers() call never passed a lang option, which
is required to include its label layers. Fixed, backed by vendored
Noto Sans Regular/Italic/Medium glyph PBFs (ranges 0-255 and 256-511
only — Basic Latin + Latin-1 Supplement + Latin Extended-A, enough for
accented Central European place names; other scripts won't render
offline). Verified against the actual offline.pmtiles vector layer
schema that the name/name:en/script fields this expects are present.

Also nudge a handful of OFFLINE_THEME color roles (background, water,
wood, buildings, the two road-importance tiers) towards the online
style's actual palette (sampled from its style JSON) so switching
Online/Offline doesn't look like two different apps — deliberately
partial, not the removed full recolor.

docs/architecture.adoc

@@ -70,59 +70,39 @@ support) just returns byte ranges of the file; pmtiles.js in the
 browser reads the archive's own directory and requests only the bytes
 it needs for the tiles on screen.
 
-=== Known limitation: no offline text labels
+=== Offline text labels and color palette
 
-The offline style only renders `protomaps-themes-base`'s non-label
-layers (roads, buildings, land use, water — no place names or street
-labels). Label rendering in MapLibre needs a "glyphs" server serving
-font PBF ranges, which would mean vendoring a font glyph set locally
-too; that has not been done, to keep the initial scope manageable.
-Revisit this if labelled offline maps turn out to matter in practice.
+Label rendering in MapLibre needs a "glyphs" server serving font PBF
+ranges (256 Unicode code points each); `data/offline.pmtiles`'s fields
+(`name`, `name:en`, `script`, ...) match what
+`protomaps-themes-base`'s `layers(source, theme, { lang: "en" })`
+expects for its label layers (verified against the actual PMTiles
+vector layer schema), so passing that option turns labels on. The
+glyphs themselves are vendored under `public/vendor/fonts/` — Noto
+Sans Regular/Italic/Medium, ranges `0-255` and `256-511`
+(Basic Latin + Latin-1 Supplement + Latin Extended-A, SIL OFL
+licensed, from
+https://github.com/protomaps/basemaps-assets[protomaps/basemaps-assets]),
+covering accented Latin place names (Slovak, Czech, Polish, German,
+...). Labels in other scripts (Cyrillic, Greek, CJK, ...) won't render
+offline, since those glyph ranges aren't vendored.
+
+`public/js/map.js`'s `OFFLINE_THEME` also nudges a handful of color
+roles (background, water, wood, buildings, the two road-importance
+tiers) from `protomaps-themes-base`'s stock "light" theme towards the
+online "liberty" style's actual palette (sampled from its style JSON),
+so Online/Offline don't look like two different apps. This is
+deliberately partial — most roles (labels, casings, minor terrain
+fills, ...) are left at their theme defaults — not the kind of
+full per-layer recolor a previous iteration of this app did (and
+removed, along with any dependency on OsmAnd's own tile server, which
+this app cannot use per OsmAnd's terms restricting tile use to "personal,
+non-commercial use within OsmAnd applications and platforms").
 
 No PMTiles file ships with the repository — it is expected to be
 supplied locally (see `docs/development.adoc`) and stays gitignored
 because such extracts are typically large binary files.
 
-=== Visual style
-
-Both styles are recolored, by `public/js/osmand-style.js`, to
-approximate the look of https://osmand.net/map[OsmAnd's own web map]
-(cream background, green forests, orange roads, purple admin
-boundaries) — deliberately *not* by using OsmAnd's tile server
-directly: its terms restrict tile use to "personal, non-commercial use
-within OsmAnd applications and platforms", which this app isn't.
-
-One shared color palette drives two independent recolorings:
-
-* *Online*: `onlineStyle()` fetches OpenFreeMap's raw "liberty" style
-  JSON and patches `paint` colors on its layers in place — matching a
-  layer to a category (water, wood, park, landuse, building, major/
-  minor road, boundary) by its id, then walking that layer's color
-  properties (`background-color`, `fill-color`, `line-color`,
-  `fill-extrusion-color`, and any `*-outline-color`) and replacing
-  every color-shaped leaf — including inside `interpolate`/other
-  expressions — with the category's palette color, leaving non-color
-  leaves (operators, zoom stops, `["get", ...]`) untouched. Labels and
-  railways are left at their original colors — only categorized layer
-  types (`background`/`fill`/`line`/`fill-extrusion`) are touched at
-  all, so `symbol` layers (all labels/icons) are never in scope.
-  Result is cached after the first fetch.
-* *Offline*: `offlineTheme()` overrides the relevant color roles on a
-  `protomaps-themes-base` `Theme` object (starting from
-  `namedTheme("light")`), leaving roles it doesn't set (labels — moot,
-  see above — rail, tunnels, POI colors) at their defaults.
-
-=== Known limitation: coarser road colors offline
-
-protomaps-themes-base's `Theme` only has two paint-relevant road tiers
-(`major` / `minor_a`+`minor_b`, plus `link` for ramps) versus
-OpenFreeMap's finer-grained classes (`road_motorway`,
-`road_trunk_primary`, `road_secondary_tertiary`, `road_minor`, ...).
-Mapping `major` to the palette's road-major orange colors more roads
-orange offline than online (protomaps' "major" bucket is broader than
-just motorway/trunk/primary) — a real difference in how coarse the two
-underlying style systems are, not a bug in the recoloring itself.
-
 == Weather radar overlay
 
 `public/js/radar.js` adds a "Radar" map control that overlays recent