Fix Android release build and verify on emulator

- Disable Kotlin incremental compilation (kotlin.incremental=false): the
  project lives on D: while Gradle's Kotlin daemon caches default to C:,
  which crashes with "this and base files have different roots" when
  closing incremental caches.
- Drop flutter_map_tile_caching for now: it pins objectbox_flutter_libs
  ^4.1.0, which fails checkReleaseAarMetadata against newer AndroidX
  transitive deps (needs compileSdk 34+, itself built against android-31).
  Not used in code yet, so deferred rather than forcing an unverified
  dependency_override.
- Add web/ platform for fast local UI iteration without an emulator.
- Ignore .claude/ (Claude Code session state, not project content).

Verified: flutter analyze, flutter test, and a real release build running
on a newly created Pixel_10a-profile Android emulator (API 36).

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

app/web/manifest.json

@@ -0,0 +1,35 @@
+{
+    "name": "dmc_app",
+    "short_name": "dmc_app",
+    "start_url": ".",
+    "display": "standalone",
+    "background_color": "#0175C2",
+    "theme_color": "#0175C2",
+    "description": "A new Flutter project.",
+    "orientation": "portrait-primary",
+    "prefer_related_applications": false,
+    "icons": [
+        {
+            "src": "icons/Icon-192.png",
+            "sizes": "192x192",
+            "type": "image/png"
+        },
+        {
+            "src": "icons/Icon-512.png",
+            "sizes": "512x512",
+            "type": "image/png"
+        },
+        {
+            "src": "icons/Icon-maskable-192.png",
+            "sizes": "192x192",
+            "type": "image/png",
+            "purpose": "maskable"
+        },
+        {
+            "src": "icons/Icon-maskable-512.png",
+            "sizes": "512x512",
+            "type": "image/png",
+            "purpose": "maskable"
+        }
+    ]
+}