Hide dormant years (2025) from the calendar year dropdown

Fixing the cumulative-total bug (previous commit) meant _team_fts_like now
spans the export's full true window, which includes trailing months from
before the person was active at all (Oct-Dec 2025, all zeros) - those were
showing up as a selectable year with nothing in it. _team_years_with_activity
keeps only years with at least one month of real net change or a real post;
2027 will appear automatically the first time it has either, same mechanism,
no code change needed then.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

app.py

@@ -2801,6 +2801,22 @@ def _team_posts_like(top_posts_df):
     return df
 
 
+def _team_years_with_activity(fts_like, posts_like):
+    """_available_years() returns every year with any row at all in the data - since
+    _team_fts_like() now spans the export's full true window (fixed to stop dropping
+    the May 30 gain), that includes trailing months from before the person was even
+    active (e.g. Oct-Dec 2025, all zeros) which would otherwise clutter the year
+    dropdown with a year where literally nothing happened. Keeps only years with at
+    least one month of real net change or a real post - 2027 appears here
+    automatically the first time it has either, no code change needed."""
+    years = []
+    for y in _available_years(fts_like, posts_like):
+        monthly_net, monthly_posts, _, _ = _monthly_summary(fts_like, posts_like, y)
+        if any(v != 0 for v in monthly_net.values()) or monthly_posts:
+            years.append(y)
+    return years
+
+
 def _team_calendar_grid(followers_daily_df, top_posts_df):
     """Same month-box grid + day-tile row as the Overview/Followers tabs' "Follower
     Gains — Calendar", now actually interactive: a year dropdown (ready for 2027 as
@@ -2810,7 +2826,7 @@ def _team_calendar_grid(followers_daily_df, top_posts_df):
     per-person callback registration."""
     fts_like = _team_fts_like(followers_daily_df)
     posts_like = _team_posts_like(top_posts_df)
-    years = _available_years(fts_like, posts_like)
+    years = _team_years_with_activity(fts_like, posts_like)
     if not years:
         return html.Div("No follower data.", className="text-muted")
     return html.Div([
@@ -2852,7 +2868,7 @@ def _update_team_calendar(year, _month_clicks, name):
     posts_like = _team_posts_like(data["top_posts"])
 
     if year is None:
-        years = _available_years(fts_like, posts_like)
+        years = _team_years_with_activity(fts_like, posts_like)
         if not years:
             raise PreventUpdate
         year = years[0]