fix: explicit tag scanning with delete UI

- Remove auto-parsing on collapse
- Add "Scan for #tags" button that parses from current textarea content
- Always show tags section with delete buttons
- Show help text when no tags exist

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/routes/+page.server.ts

@@ -296,6 +296,7 @@ export const actions: Actions = {
 	parseTags: async ({ request }) => {
 		const formData = await request.formData();
 		const id = formData.get('id')?.toString();
+		const content = formData.get('content')?.toString();
 
 		if (!id) {
 			return fail(400, { error: 'Entry ID is required' });
@@ -306,8 +307,9 @@ export const actions: Actions = {
 			return fail(404, { error: 'Entry not found' });
 		}
 
-		// Parse hashtags from current content and merge with existing tags
-		const newTags = parseHashtags(existing.content);
+		// Parse hashtags from provided content (or fall back to database content)
+		const textToParse = content ?? existing.content;
+		const newTags = parseHashtags(textToParse);
 		const existingTags = tagRepository.getByEntryId(id).map((t) => t.name.toLowerCase());
 		const allTags = [...new Set([...existingTags, ...newTags])];
 		tagRepository.updateEntryTags(id, allTags);