Improve space launch change email format for better readability

Replace technical YAML diff output with human-readable bullet points that clearly explain what changed. Added structured email format with mission details, rocket emoji, and formatted dates.

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

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

update.py

@@ -109,26 +109,94 @@ Agenda: https://edwardbetts.com/agenda/
     agenda.mail.send_mail(config, subject, body)
 
 
+def format_launch_changes(differences: dict) -> str:
+    """Convert deepdiff output to human-readable format."""
+    changes = []
+    # Handle value changes
+    if "values_changed" in differences:
+        for path, change in differences["values_changed"].items():
+            field = path.replace("root['", "").replace("']", "").replace("root.", "")
+            old_val = change["old_value"]
+            new_val = change["new_value"]
+            # Format specific fields nicely
+            if field == "net":
+                try:
+                    old_dt = datetime.fromisoformat(old_val.replace('Z', '+00:00'))
+                    new_dt = datetime.fromisoformat(new_val.replace('Z', '+00:00'))
+                    changes.append(f"Launch time changed from {old_dt.strftime('%d %b %Y at %H:%M UTC')} to {new_dt.strftime('%d %b %Y at %H:%M UTC')}")
+                except:
+                    changes.append(f"Launch time changed from {old_val} to {new_val}")
+            elif field == "name":
+                changes.append(f"Mission name changed from '{old_val}' to '{new_val}'")
+            elif field == "probability":
+                if old_val is None:
+                    changes.append(f"Launch probability set to {new_val}%")
+                elif new_val is None:
+                    changes.append("Launch probability removed")
+                else:
+                    changes.append(f"Launch probability changed from {old_val}% to {new_val}%")
+            elif "status" in field:
+                changes.append(f"Status changed from '{old_val}' to '{new_val}'")
+            else:
+                changes.append(f"{field.replace('_', ' ').title()} changed from '{old_val}' to '{new_val}'")
+    # Handle additions
+    if "dictionary_item_added" in differences:
+        for path in differences["dictionary_item_added"]:
+            field = path.replace("root['", "").replace("']", "").replace("root.", "")
+            changes.append(f"New field added: {field.replace('_', ' ').title()}")
+    # Handle removals
+    if "dictionary_item_removed" in differences:
+        for path in differences["dictionary_item_removed"]:
+            field = path.replace("root['", "").replace("']", "").replace("root.", "")
+            changes.append(f"Field removed: {field.replace('_', ' ').title()}")
+    # Handle type changes
+    if "type_changes" in differences:
+        for path, change in differences["type_changes"].items():
+            field = path.replace("root['", "").replace("']", "").replace("root.", "")
+            changes.append(f"{field.replace('_', ' ').title()} type changed from {change['old_type'].__name__} to {change['new_type'].__name__}")
+    return "\n".join(f"• {change}" for change in changes) if changes else "No specific changes detected"
+
+
 def report_space_launch_change(
     config: flask.config.Config, prev_launch: StrDict | None, cur_launch: StrDict | None
 ) -> None:
     """Send mail to announce change to space launch data."""
     if cur_launch:
         name = cur_launch["name"]
+        status = cur_launch.get("status", {}).get("name", "Unknown") if isinstance(cur_launch.get("status"), dict) else "Unknown"
+        launch_date = cur_launch.get("net", "Unknown")
+        location = cur_launch.get("pad", {}).get("location", {}).get("name", "Unknown") if isinstance(cur_launch.get("pad"), dict) else "Unknown"
     else:
         assert prev_launch
         name = prev_launch["name"]
-    subject = f"Change to {name}"
+        status = "Cancelled/Removed"
+        launch_date = prev_launch.get("net", "Unknown")
+        location = prev_launch.get("pad", {}).get("location", {}).get("name", "Unknown") if isinstance(prev_launch.get("pad"), dict) else "Unknown"
+    subject = f"Space Launch Update: {name}"
 
     differences = deepdiff.DeepDiff(prev_launch, cur_launch)
+    changes_text = format_launch_changes(differences)
+    # Format launch date nicely
+    formatted_date = "Unknown"
+    if launch_date and launch_date != "Unknown":
+        try:
+            dt = datetime.fromisoformat(launch_date.replace('Z', '+00:00'))
+            formatted_date = dt.strftime('%d %b %Y at %H:%M UTC')
+        except:
+            formatted_date = launch_date
 
-    body = f"""
-A space launch of interest was updated.
+    body = f"""🚀 Space Launch Update
 
-{yaml.dump(differences)}
+Mission: {name}
+Status: {status}
+Launch Date: {formatted_date}
+Location: {location}
 
-https://edwardbetts.com/agenda/launches
-    """
+Changes:
+{changes_text}
+
+View all launches: https://edwardbetts.com/agenda/launches
+"""
 
     agenda.mail.send_mail(config, subject, body)