feat(web): improve web build configuration and accessibility

- Add source maps and web renderer build arguments with defaults
- Configure Caddy with CSP headers, cache policies, and service worker handling
- Defer loading of import screen for performance optimization
- Add semantic labels to icons for accessibility
- Update web index.html with Swedish language, meta tags, and description
- Add robots.txt and lighthouse configuration
- Add new planning documents and archive entries

flutter/lib/features/inventory/presentation/swipeable_inventory_tile.dart

@@ -39,8 +39,9 @@ double _stepForUnit(String unit) {
 
 /// Formats a step value for display: whole numbers without decimal,
 /// fractions with one decimal.
-String _fmtStep(double step) =>
-    step == step.roundToDouble() ? step.toStringAsFixed(0) : step.toStringAsFixed(1);
+String _fmtStep(double step) => step == step.roundToDouble()
+    ? step.toStringAsFixed(0)
+    : step.toStringAsFixed(1);
 
 /// A [ListTile] wrapped in a swipe-to-adjust widget.
 ///
@@ -122,7 +123,8 @@ class _SwipeableInventoryTileState
         // Decrease: use consume endpoint so history is preserved.
         // Guard against going below zero.
         if (widget.item.quantity <= 0) return;
-        final consume = step > widget.item.quantity ? widget.item.quantity : step;
+        final consume =
+            step > widget.item.quantity ? widget.item.quantity : step;
         await repo.consumeInventoryItem(
           widget.item.id,
           amountUsed: consume,
@@ -402,32 +404,44 @@ class _TrailingActions extends ConsumerWidget {
         Tooltip(
           message: 'Konsumera',
           child: IconButton(
-            icon: const Icon(Icons.remove_circle_outline),
+            icon: const Icon(
+              Icons.remove_circle_outline,
+              semanticLabel: 'Konsumera',
+            ),
             onPressed: () => context.push('/inventory/${item.id}/consume'),
           ),
         ),
         Tooltip(
           message: 'Redigera',
           child: IconButton(
-            icon: const Icon(Icons.edit_outlined),
+            icon: const Icon(
+              Icons.edit_outlined,
+              semanticLabel: 'Redigera',
+            ),
             onPressed: () => context.push('/inventory/${item.id}/edit'),
           ),
         ),
         Tooltip(
           message: 'Flytta till baslager',
           child: IconButton(
-            icon: const Icon(Icons.storefront_outlined),
+            icon: const Icon(
+              Icons.storefront_outlined,
+              semanticLabel: 'Flytta till baslager',
+            ),
             onPressed: () async {
               try {
                 final token = await ref.read(authStateProvider.future);
-                await ref.read(inventoryRepositoryProvider).moveInventoryItemToPantry(
+                await ref
+                    .read(inventoryRepositoryProvider)
+                    .moveInventoryItemToPantry(
                       item.id,
                       token: token,
                     );
                 ref.invalidate(inventoryProvider);
               } catch (e) {
                 ScaffoldMessenger.of(context).showSnackBar(
-                  buildCopyableErrorSnackBar(context, mapErrorToUserMessage(e, context)),
+                  buildCopyableErrorSnackBar(
+                      context, mapErrorToUserMessage(e, context)),
                 );
               }
             },
@@ -449,7 +463,11 @@ class _DeleteButton extends ConsumerWidget {
     return Tooltip(
       message: 'Ta bort',
       child: IconButton(
-        icon: const Icon(Icons.delete_outline, color: Colors.red),
+        icon: const Icon(
+          Icons.delete_outline,
+          color: Colors.red,
+          semanticLabel: 'Ta bort',
+        ),
         onPressed: () async {
           final confirmed = await showDialog<bool>(
             context: context,
@@ -477,7 +495,8 @@ class _DeleteButton extends ConsumerWidget {
               ref.invalidate(inventoryProvider);
             } catch (e) {
               ScaffoldMessenger.of(context).showSnackBar(
-                buildCopyableErrorSnackBar(context, mapErrorToUserMessage(e, context)),
+                buildCopyableErrorSnackBar(
+                    context, mapErrorToUserMessage(e, context)),
               );
             }
           }
@@ -486,4 +505,3 @@ class _DeleteButton extends ConsumerWidget {
     );
   }
 }
-