Fix Players page KeyError + use_container_width deprecation

- Players page: fix regression_chart xg_col default (goals_p90 -> xg_p90)
- charts.py: make regression_chart defensive against missing columns
- All pages: replace use_container_width=True with width='stretch'
- Verified: all 5 pages render with zero errors via Playwright browser test

dashboard/pages/01_matchday.py

@@ -11,7 +11,7 @@ import streamlit as st
 from dashboard.warehouse import load_predictions, load_fixtures, load_players, load_lineups, load_votes
 from dashboard.viz.components import inject_css, kpi_card, section, insight, role_chip
 from dashboard.viz.charts import fixture_heatmap, kpi_sparkline, error_violins
-from dashboard.viz.template import PITCH_GREEN, GOLD, RED, SKY, VIOLET, WHITE, TEXT_SECONDARY, ROLE_COLORS, ROLE_ICONS
+from dashboard.viz.template import PITCH_GREEN, GOLD, RED, SKY, VIOLET, WHITE, TEXT_SECONDARY, ROLE_COLORS, ROLE_ICONS, FANTABETO_TEMPLATE
 
 
 @st.cache_data(ttl=3600)
@@ -87,7 +87,7 @@ def run():
         ), unsafe_allow_html=True)
     with k4:
         st.plotly_chart(kpi_sparkline(trend, "FV Trend", PITCH_GREEN),
-                        use_container_width=True, config={"displayModeBar": False})
+                        width="stretch", config={"displayModeBar": False})
         st.caption("Last 5 GW trend")
 
     st.divider()
@@ -98,7 +98,7 @@ def run():
         section("📅 Fixture Difficulty")
         heatmap_df = _build_fixture_heatmap(players, fixtures)
         fig = fixture_heatmap(heatmap_df)
-        st.plotly_chart(fig, use_container_width=True)
+        st.plotly_chart(fig, width="stretch")
         insight("Warmer colors = tougher opponent. Based on opponent avg FV from 25/26.")
 
     with c2:
@@ -132,7 +132,7 @@ def run():
     ]
     show.columns = ["Player", "Role", "Team", "H/A", "Opponent", "Projected FV", "Status"]
     st.dataframe(
-        show, use_container_width=True, hide_index=True,
+        show, width="stretch", hide_index=True,
         column_config={
             "Player": st.column_config.TextColumn(width="medium"),
             "Projected FV": st.column_config.TextColumn(width="small"),
@@ -151,7 +151,6 @@ def run():
     ranks = list(np.cumsum(np.diff([8] + ranks, prepend=8).clip(-2, 2)))
 
     import plotly.graph_objects as go
-    from dashboard.viz.template import FANTABETO_TEMPLATE, PITCH_GREEN, SKY, TEXT_SECONDARY
 
     fig = go.Figure()
     fig.add_trace(go.Scatter(
@@ -167,7 +166,7 @@ def run():
         xaxis=dict(title=""),
         margin=dict(l=10, r=10, t=10, b=10),
     )
-    st.plotly_chart(fig, use_container_width=True)
+    st.plotly_chart(fig, width="stretch")
 
 
 if __name__ == "__main__":