fix: avoid duplicate H1 when template begins with one

`buildNoteBody` unconditionally prepended an empty `# ` placeholder
whenever `initialEmptyHeading` was true, which collided with templates
whose first line is already an H1 (e.g. a Weekly Notes type whose
template starts with `# Woche 2026.21`). The placeholder is now
suppressed when the template's first non-whitespace line is `# `.

Fixes: https://github.com/refactoringhq/tolaria/issues/736

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/hooks/useNoteCreation.test.ts

@@ -148,6 +148,28 @@ describe('buildNoteContent', () => {
     })
     expect(content).toBe('---\ntype: Project\nstatus: Active\n---\n\n# \n\n## Objective\n\n')
   })
+
+  it('skips the empty H1 when the template already starts with one', () => {
+    const content = buildNoteContent({
+      title: null,
+      type: 'Weekly',
+      status: null,
+      template: '# Woche 2026.21\n\nWochennotiz\n',
+      initialEmptyHeading: true,
+    })
+    expect(content).toBe('---\ntype: Weekly\n---\n\n# Woche 2026.21\n\nWochennotiz\n')
+  })
+
+  it('skips the empty H1 when the template starts with an H1 after leading whitespace', () => {
+    const content = buildNoteContent({
+      title: null,
+      type: 'Weekly',
+      status: null,
+      template: '\n\n# Woche 2026.21\n',
+      initialEmptyHeading: true,
+    })
+    expect(content).toBe('---\ntype: Weekly\n---\n\n\n\n# Woche 2026.21\n')
+  })
 })
 
 describe('resolveNewNote', () => {

src/hooks/useNoteCreation.ts

@@ -117,7 +117,8 @@ export interface TypeInstanceDefault {
 }
 
 function buildNoteBody({ template, initialEmptyHeading }: Pick<NoteContentParams, 'template' | 'initialEmptyHeading'>): string {
-  if (initialEmptyHeading) {
+  const templateStartsWithH1 = template?.trimStart().startsWith('# ') ?? false
+  if (initialEmptyHeading && !templateStartsWithH1) {
     return template ? `\n# \n\n${template}` : '\n# \n\n'
   }
   return template ? `\n${template}` : ''