Add the region map, permanent attribution and the Sources screen

Puts a MapLibre map on screen framed on the region, with the credit
obligations that come with showing third-party data satisfied structurally
rather than by remembering to add a label.

The base map style comes from MAP_STYLE_URL, and with no key configured the
app generates a fallback style from the region's own bounding box: a flat
background and the extent outline, no network sources at all. That keeps a
fresh clone runnable offline without pulling in a boundary dataset that would
carry its own licence, and it deliberately looks like a placeholder so it is
not mistaken for a finished map.

Attribution is driven by what is actually rendered. The bar lists the credits
for the active sources only, because crediting OpenStreetMap while showing the
fallback style would be a false attribution, and it says plainly when no base
map is configured. It sits below the map rather than floating over it so no
map control or gesture overlay can occlude a credit that the ODbL and CC BY-SA
terms require to be visible.

The Sources screen leads with the independence disclaimer, before the sources
it qualifies, so a reader who stops after the first screenful has still seen
it. Sources with no stated licence — ARPA publishes none for the alert
bulletin — say so explicitly rather than being shown bare or given an invented
one. A separate note explains that the rendered radar frames inherit CC BY-SA
from the DPC source data.

Also declares the INTERNET permission in the main manifest: Flutter injects it
into the debug and profile manifests only, so a release build would otherwise
fail every request on device.

Verified: analyze clean, 66 tests passing, appbundle builds with the native
MapLibre plugin. Not verified visually — this machine has no Android device or
emulator image, so nobody has watched the map render.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

Nuvolari/app/pubspec.lock

@@ -1,6 +1,14 @@
 # Generated by pub
 # See https://dart.dev/tools/pub/glossary#lockfile
 packages:
+  archive:
+    dependency: transitive
+    description:
+      name: archive
+      sha256: ace891da0862b0e4cabbb064ee3fd87b2728b898949fdb366d83fe98342c9f19
+      url: "https://pub.dev"
+    source: hosted
+    version: "4.2.0"
   async:
     dependency: transitive
     description:
@@ -57,6 +65,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "1.3.3"
+  ffi:
+    dependency: transitive
+    description:
+      name: ffi
+      sha256: "6d7fd89431262d8f3125e81b50d3847a091d846eafcd4fdb88dd06f36d705a45"
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.2.0"
   fixnum:
     dependency: transitive
     description:
@@ -96,6 +112,19 @@ packages:
     description: flutter
     source: sdk
     version: "0.0.0"
+  flutter_web_plugins:
+    dependency: transitive
+    description: flutter
+    source: sdk
+    version: "0.0.0"
+  image:
+    dependency: transitive
+    description:
+      name: image
+      sha256: "1976370a4df3091bb0f72409c187ad1f9132a818bc6b95ca59c0bae1c75c688e"
+      url: "https://pub.dev"
+    source: hosted
+    version: "4.9.2"
   intl:
     dependency: "direct main"
     description:
@@ -144,6 +173,30 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "1.0.1"
+  maplibre_gl:
+    dependency: "direct main"
+    description:
+      name: maplibre_gl
+      sha256: "52e5c873137f8bcb2646802cf1d811575cb4b5bab52d1373d8d23a48f656f166"
+      url: "https://pub.dev"
+    source: hosted
+    version: "0.27.1"
+  maplibre_gl_platform_interface:
+    dependency: transitive
+    description:
+      name: maplibre_gl_platform_interface
+      sha256: "476b1a8bd62465d7891218845118cb106df29c17f9034ff1a0cce7dd153179e3"
+      url: "https://pub.dev"
+    source: hosted
+    version: "0.27.1"
+  maplibre_gl_web:
+    dependency: transitive
+    description:
+      name: maplibre_gl_web
+      sha256: "3c0e9084edbe7d860f2366f8d6658722c79f3722a4e1234f3e49251a57f8297a"
+      url: "https://pub.dev"
+    source: hosted
+    version: "0.27.1"
   matcher:
     dependency: transitive
     description:
@@ -176,6 +229,22 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "1.9.1"
+  plugin_platform_interface:
+    dependency: transitive
+    description:
+      name: plugin_platform_interface
+      sha256: "4820fbfdb9478b1ebae27888254d445073732dae3d6ea81f0b7e06d5dedc3f02"
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.1.8"
+  posix:
+    dependency: transitive
+    description:
+      name: posix
+      sha256: bc1bad54ad2b735816e31f8d4600cfde6c7839975085ddfbca48b6c9f7c4044e
+      url: "https://pub.dev"
+    source: hosted
+    version: "6.5.2"
   riverpod:
     dependency: transitive
     description:
@@ -253,6 +322,70 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "1.4.0"
+  url_launcher:
+    dependency: "direct main"
+    description:
+      name: url_launcher
+      sha256: f6a7e5c4835bb4e3026a04793a4199ca2d14c739ec378fdfe23fc8075d0439f8
+      url: "https://pub.dev"
+    source: hosted
+    version: "6.3.2"
+  url_launcher_android:
+    dependency: transitive
+    description:
+      name: url_launcher_android
+      sha256: "611e87fb320b70d1dd721dc46af89c98aceccea9b31fde49e084591414e0c610"
+      url: "https://pub.dev"
+    source: hosted
+    version: "6.3.33"
+  url_launcher_ios:
+    dependency: transitive
+    description:
+      name: url_launcher_ios
+      sha256: "8faa1aab294f1ab4040b43660c887b0418d5fa4f0cffef76a484e6aa1092eb4a"
+      url: "https://pub.dev"
+    source: hosted
+    version: "6.4.2"
+  url_launcher_linux:
+    dependency: transitive
+    description:
+      name: url_launcher_linux
+      sha256: "10f86fef4c2c43563fa6c211ff9cf757adf4d3ab762c56bd430664a947d70cd0"
+      url: "https://pub.dev"
+    source: hosted
+    version: "3.2.3"
+  url_launcher_macos:
+    dependency: transitive
+    description:
+      name: url_launcher_macos
+      sha256: "5e835a3b869c2d70325349c81c5a45c28e20791265b67b2669da6b08c5cd5201"
+      url: "https://pub.dev"
+    source: hosted
+    version: "3.2.6"
+  url_launcher_platform_interface:
+    dependency: transitive
+    description:
+      name: url_launcher_platform_interface
+      sha256: "552f8a1e663569be95a8190206a38187b531910283c3e982193e4f2733f01029"
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.3.2"
+  url_launcher_web:
+    dependency: transitive
+    description:
+      name: url_launcher_web
+      sha256: "85c81589622fbc87c1c683aaea164d3604a7777495a79d91e39ffcdec39ddb34"
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.4.3"
+  url_launcher_windows:
+    dependency: transitive
+    description:
+      name: url_launcher_windows
+      sha256: "6c5ad3f22cd4c38e089b81963b3cd7bb83b111b2df5dce008bb066162f42e429"
+      url: "https://pub.dev"
+    source: hosted
+    version: "3.1.6"
   uuid:
     dependency: transitive
     description:
@@ -277,6 +410,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "15.3.0"
+  web:
+    dependency: transitive
+    description:
+      name: web
+      sha256: "868d88a33d8a87b18ffc05f9f030ba328ffefba92d6c127917a2ba740f9cfe4a"
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.1.1"
 sdks:
   dart: ">=3.13.3 <4.0.0"
-  flutter: ">=3.18.0-18.0.pre.54"
+  flutter: ">=3.44.0"