Merge main into prereq-10-osm-overlays and port Open Map Overlays

Main moved on since this PR opened; the overlay layer is ported to the
current contracts:

- Layer-state token 6 (j belongs to transit; new single-character
  tokens are digits) with a reservation-ledger row, and the option owner
  renamed to the layer id so the compact share codec can encode it.
- Constructed per catalog by createOsmOverlaysLayer() in
  constructCatalog.js; src/standalone/data.js no longer registers layers.
- Drapes through maps/imageryHost.js, so the overlays show on Google 3D
  (tileset imagery) as well as the globe stacks, and follow map-stack
  switches. Imagery layers are created on enable and destroyed on
  disable/destroy.
- Translated chip labels and layer name in every locale, LAYER_NAME_KEYS,
  Infrastructure panel group, voice manifest entry.
- Attribution: OpenSeaMap tiles CC BY-SA 2.0, OpenSnowMap credit as
  required, OSM ODbL credit for both; bulk-download note in DATA_SOURCES.
- CURRENT-STATE row, changelog fragment, share-codec absent defaults,
  updated token-ledger fixtures and voice schema pins.

src/data/layerStateTokenReservations.json

@@ -0,0 +1,35 @@
+[
+  ["air-quality", "4"],
+  ["ais-live-vessels", "a"],
+  ["alpr-cameras", "p"],
+  ["bhote-koshi-2026", "h"],
+  ["bhote-koshi-locator", "z"],
+  ["bikeshare", "b"],
+  ["cctv", "c"],
+  ["directions", "n"],
+  ["earthquakes", "e"],
+  ["fire-perimeters", "2"],
+  ["flights", "f"],
+  ["gnss-integrity", "3"],
+  ["local-dams", "q"],
+  ["local-datacenters", "d"],
+  ["local-firms", "w"],
+  ["military", "m"],
+  ["military-awareness", "g"],
+  ["military-installations", "i"],
+  ["osm-overlays", "6"],
+  ["radio", "r"],
+  ["recent-imagery", "1"],
+  ["rocket-launches", "x"],
+  ["s2-ghostmaps", "5"],
+  ["satellites", "s"],
+  ["street-level", "0"],
+  ["telegeography-submarine-cables", "u"],
+  ["traffic", "t"],
+  ["transit", "j"],
+  ["weather-cyclones", "y"],
+  ["weather-lightning", "l"],
+  ["weather-radar", "v"],
+  ["weather-satellite", "o"],
+  ["wind", "k"]
+]