feat(media): Add HEIC/HEIF image support - v1.4.2

- Add pillow-heif dependency for iPhone photo support
- Auto-convert HEIC to JPEG (browsers can't display HEIC)
- Graceful error if pillow-heif not installed
- Handles RGBA/P mode conversion to RGB

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

starpunk/media.py

@@ -19,6 +19,14 @@ import io
 from typing import Optional, List, Dict, Tuple
 from flask import current_app
 
+# HEIC/HEIF support - import registers with Pillow automatically
+try:
+    import pillow_heif
+    pillow_heif.register_heif_opener()
+    HEIC_SUPPORTED = True
+except ImportError:
+    HEIC_SUPPORTED = False
+
 # Allowed MIME types per Q11
 ALLOWED_MIME_TYPES = {
     'image/jpeg': ['.jpg', '.jpeg'],
@@ -68,19 +76,21 @@ def get_optimization_params(file_size: int) -> Tuple[int, int]:
         return (1280, 85)
 
 
-def validate_image(file_data: bytes, filename: str) -> Tuple[str, int, int]:
+def validate_image(file_data: bytes, filename: str) -> Tuple[bytes, str, int, int]:
     """
     Validate image file
 
     Per Q11: Validate MIME type using Pillow
     Per Q6: Reject if >50MB or >4096px (updated v1.4.0)
+    Per v1.4.2: Convert HEIC to JPEG (browsers cannot display HEIC)
 
     Args:
         file_data: Raw file bytes
         filename: Original filename
 
     Returns:
-        Tuple of (mime_type, width, height)
+        Tuple of (file_data, mime_type, width, height)
+        Note: file_data may be converted (e.g., HEIC to JPEG)
 
     Raises:
         ValueError: If file is invalid
@@ -100,6 +110,25 @@ def validate_image(file_data: bytes, filename: str) -> Tuple[str, int, int]:
     except Exception as e:
         raise ValueError(f"Invalid or corrupted image: {e}")
 
+    # HEIC/HEIF conversion (v1.4.2)
+    # HEIC cannot be displayed in browsers, convert to JPEG
+    if img.format in ('HEIF', 'HEIC'):
+        if not HEIC_SUPPORTED:
+            raise ValueError(
+                "HEIC/HEIF images require pillow-heif library. "
+                "Please convert to JPEG before uploading."
+            )
+        # Convert HEIC to JPEG in memory
+        output = io.BytesIO()
+        # Convert to RGB if needed (HEIC may have alpha channel)
+        if img.mode in ('RGBA', 'P'):
+            img = img.convert('RGB')
+        img.save(output, format='JPEG', quality=95)
+        output.seek(0)
+        # Re-open as JPEG for further processing
+        file_data = output.getvalue()
+        img = Image.open(io.BytesIO(file_data))
+
     # Check format is allowed
     if img.format:
         format_lower = img.format.lower()
@@ -135,7 +164,7 @@ def validate_image(file_data: bytes, filename: str) -> Tuple[str, int, int]:
             # Not animated, continue normally
             pass
 
-    return mime_type, width, height
+    return file_data, mime_type, width, height
 
 
 def optimize_image(image_data: bytes, original_size: int = None) -> Tuple[Image.Image, int, int, bytes]:
@@ -395,9 +424,9 @@ def save_media(file_data: bytes, filename: str) -> Dict:
     file_size = len(file_data)
 
     try:
-        # Validate image (returns 3-tuple, signature unchanged)
+        # Validate image (returns 4-tuple with potentially converted bytes)
         try:
-            mime_type, orig_width, orig_height = validate_image(file_data, filename)
+            file_data, mime_type, orig_width, orig_height = validate_image(file_data, filename)
         except ValueError as e:
             current_app.logger.warning(
                 f'Media upload validation failed: filename="{filename}", '