feat(input): Wire up camera and OCR scanner buttons

lib/features/input/input_screen.dart

@@ -210,17 +210,66 @@ class _InputScreenState extends State<InputScreen> {
   }
   
   void _onCameraTap() {
-    // TODO: Implement camera capture
-    ScaffoldMessenger.of(context).showSnackBar(
-      const SnackBar(content: Text('Camera - Coming soon')),
-    );
+    // Camera tap also opens OCR scanner (same functionality)
+    _openOcrScanner();
   }
   
   void _onOcrTap() {
-    // TODO: Implement OCR scanning
-    ScaffoldMessenger.of(context).showSnackBar(
-      const SnackBar(content: Text('OCR - Coming soon')),
-    );
+    _openOcrScanner();
+  }
+  
+  Future<void> _openOcrScanner() async {
+    if (_isProcessing) return;
+    
+    setState(() => _isProcessing = true);
+    
+    try {
+      final result = await Navigator.of(context).push<OcrCaptureResult>(
+        MaterialPageRoute(
+          builder: (context) => const OcrCaptureScreen(
+            enableLivePreview: true,
+            keepImage: false,
+          ),
+        ),
+      );
+      
+      if (result != null && result.text.isNotEmpty) {
+        // Append or replace text based on current content
+        if (_textController.text.isEmpty) {
+          _textController.text = result.text;
+        } else {
+          // Append with newline separator
+          _textController.text = '${_textController.text}\n\n${result.text}';
+        }
+        
+        // Move cursor to end
+        _textController.selection = TextSelection.fromPosition(
+          TextPosition(offset: _textController.text.length),
+        );
+        
+        if (mounted) {
+          ScaffoldMessenger.of(context).showSnackBar(
+            SnackBar(
+              content: Text('Extracted ${result.blocks.length} text blocks'),
+              backgroundColor: Colors.green,
+            ),
+          );
+        }
+      }
+    } catch (e) {
+      if (mounted) {
+        ScaffoldMessenger.of(context).showSnackBar(
+          SnackBar(
+            content: Text('OCR failed: $e'),
+            backgroundColor: Colors.red,
+          ),
+        );
+      }
+    } finally {
+      if (mounted) {
+        setState(() => _isProcessing = false);
+      }
+    }
   }
   
   void _onVoiceTap() {