feat(layers): add shipwrecks layer (EMODnet + Wikidata)

A new Events layer maps shipwrecks with a card per wreck:
- EMODnet Human Activities heritage shipwrecks (about 6,500 in European
  waters, CC BY 4.0), skipping rows taken from wrecksite.eu.
- Wikidata shipwrecks with a Wikipedia article plus sinking events
  (CC0); an event folds into its ship for the date and death toll.
- A same-origin /api/shipwrecks proxy refreshes once a day and serves
  the last snapshot as stale for up to a week.

Markers are a boat icon coloured by era and sized by deaths; four era
chips filter the layer. The card follows the air-accidents layout
(deaths first). Text that names people is dropped; victims appear as
a count only.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

src/i18n/same-as-english.json

@@ -1,6 +1,7 @@
 {
   "ar": [
     "1090 MHz",
+    "1900–1945",
     "978 MHz UAT",
     "AIS: --",
     "AIS: {name}",
@@ -35,6 +36,7 @@
   ],
   "de": [
     "1090 MHz",
+    "1900–1945",
     "978 MHz UAT",
     "AIS: --",
     "AIS: {name}",
@@ -206,6 +208,7 @@
   ],
   "es": [
     "1090 MHz",
+    "1900–1945",
     "978 MHz UAT",
     "AIS: --",
     "AIS: {name}",
@@ -338,6 +341,7 @@
   ],
   "fr": [
     "1090 MHz",
+    "1900–1945",
     "978 MHz UAT",
     "ALTITUDE",
     "ALTITUDE · FT",
@@ -523,6 +527,7 @@
   ],
   "it": [
     "1090 MHz",
+    "1900–1945",
     "978 MHz UAT",
     "AFRICA",
     "AIS: --",
@@ -698,6 +703,7 @@
   ],
   "ja": [
     "1090 MHz",
+    "1900–1945",
     "978 MHz UAT",
     "AIS: --",
     "AIS: {name}",
@@ -748,6 +754,7 @@
   ],
   "pt": [
     "1090 MHz",
+    "1900–1945",
     "978 MHz UAT",
     "AIS: --",
     "AIS: {name}",
@@ -880,6 +887,7 @@
     "≥ {value} MW"
   ],
   "ru": [
+    "1900–1945",
     "AIS: --",
     "AIS: {name}",
     "CCTV",
@@ -898,6 +906,7 @@
     "WHOT/BHOT"
   ],
   "uk": [
+    "1900–1945",
     "AIS: --",
     "AIS: {name}",
     "CCTV",
@@ -912,6 +921,7 @@
   ],
   "zh-CN": [
     "1090 MHz",
+    "1900–1945",
     "978 MHz UAT",
     "AIS: --",
     "AIS: {name}",
@@ -970,6 +980,7 @@
   ],
   "zh-Hant": [
     "1090 MHz",
+    "1900–1945",
     "978 MHz UAT",
     "AIS: --",
     "AIS: {name}",