fix FT note→post renames in test_sharing & test_layout_and_styling; note page layout polish

- test_sharing.py: NotePage→PostPage, MyNotesPage→MyPostsPage, add_note_item→add_post_line,
  share_note_with→share_post_with, get_note_owner→get_post_owner; navigate to /billboard/
- test_layout_and_styling.py: NotePage→PostPage, get_item_input_box→get_line_input_box,
  add_note_item→add_post_line; navigate to /billboard/
- my_notes.html: remove "My Notes" h2 heading
- _note.scss: .note-page padding 0.75rem 1.5rem; .note-don-doff top:-1rem (DON centers on
  corner), gap:0.4rem (tight like game kit); .note-item padding-left:1.25rem (left buffer)

Code architected by Disco DeDisco <discodedisco@outlook.com>
Git commit message Co-Authored-By:
Claude Sonnet 4.6 <noreply@anthropic.com>

src/static_src/scss/_note.scss

@@ -45,7 +45,7 @@
 // ── Notes page ─────────────────────────────────────────────────────────────
 
 .note-page {
-    padding: 0.75rem;
+    padding: 0.75rem 1.5rem;
 }
 
 .note-list {
@@ -65,10 +65,10 @@
 .note-don-doff {
     position: absolute;
     left: -1rem;
-    top: 0;
+    top: -1rem;
     display: flex;
     flex-direction: column;
-    gap: 1.25rem;
+    gap: 0.4rem;
     z-index: 1;
 
     .btn { margin: 0; }
@@ -80,7 +80,7 @@
     flex-direction: row;
     align-items: flex-start;
     gap: 0.75rem;
-    padding: 0.75rem;
+    padding: 0.75rem 0.75rem 0.75rem 1.25rem;
     background-color: rgba(var(--tooltip-bg), 0.75);
     backdrop-filter: blur(6px);
     border: 0.1rem solid rgba(var(--secUser), 0.4);