fix: mobile layout, task clicks, list tab corners, hashtags in URLs

Mobile
- Plus button in triage did nothing: the stored action returned the
  capture function instead of calling it
- Workspace: tabs share the full width; save status sits as an icon next
  to the note title instead of wrapping into its own row; "Neue Notiz" /
  "Neuer Ordner" only in the top menu (and +), not repeated in the list
- Outliner fields measured while hidden stayed one line high (cut-off
  callout); they are measured again when their width changes
- Task dialog: scrolls in a div instead of a fieldset, height in dvh,
  notes editor grows with its text, so long notes are fully reachable

Desktop
- Delete button of the selected task/shopping list sits inside the tab as
  its own rounded button (matches rounded themes like Soft)

Both
- Tasks sometimes did not open: every reload after an action replaced the
  list with a loading placeholder, swallowing clicks; reloads are now
  silent after the first load of a list, stale responses are dropped
- Hashtags need whitespace or "(" before "#", so URL anchors are no
  longer tags (server, browser); one-time cleanup of stored anchor tags

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

internal/domain/models.go

@@ -21,7 +21,31 @@ func NowISO() string {
 	return time.Now().UTC().Format(time.RFC3339)
 }
 
-var hashtagRegex = regexp.MustCompile(`#([a-zA-Z0-9äöüÄÖÜß_-]+)`)
+// A hashtag starts the text or follows whitespace or "(". Fragments in links (example.com/blog#ueberschrift)
+// and words like "C#" are not tags. The browser uses the same rule (lib/markdown.tsx, lib/api.ts).
+var hashtagRegex = regexp.MustCompile(`(?:^|[\s(])#([a-zA-Z0-9äöüÄÖÜß_-]+)`)
+
+// legacyHashtagRegex is the rule before anchors were excluded; only used to clean up stored tags.
+var legacyHashtagRegex = regexp.MustCompile(`#([a-zA-Z0-9äöüÄÖÜß_-]+)`)
+
+// StaleAnchorTags returns tags the old rule found in content that the current rule does not, i.e. tags that
+// only came from URL fragments and similar.
+func StaleAnchorTags(content string) []string {
+	current := map[string]bool{}
+	for _, t := range ExtractTags(content) {
+		current[t] = true
+	}
+	var stale []string
+	seen := map[string]bool{}
+	for _, m := range legacyHashtagRegex.FindAllStringSubmatch(content, -1) {
+		t := strings.ToLower(m[1])
+		if !current[t] && !seen[t] {
+			seen[t] = true
+			stale = append(stale, t)
+		}
+	}
+	return stale
+}
 
 // ExtractTags extracts #hashtags from content
 func ExtractTags(content string) []string {
@@ -78,7 +102,7 @@ func FormatGermanDateTime(isoStr string) string {
 		time.May:       "Mai",
 		time.June:      "Juni",
 		time.July:      "Juli",
-		time.August:     "Aug.",
+		time.August:    "Aug.",
 		time.September: "Sept.",
 		time.October:   "Okt.",
 		time.November:  "Nov.",