Show loading spinners next to each instrument value during conditions fetch

- Add _conditionsLoading StateFlow to MainViewModel; set true when
  loadConditions() fires, false when the fetch completes (success or fail)
- Cancel any in-flight conditions job when a new loadConditions() call
  arrives (e.g. rapid map pans) so only the latest fetch drives the state
- Add a 10dp ProgressBar after each of the six data values in
  layout_instruments_sheet.xml (wind, temp, baro, current, waves, swell);
  visibility GONE by default, alpha 0.5; header section tinted
  colorOnSurfaceVariant, forecast section tinted #5B9EC2 to match its labels
- Observe conditionsLoading in MainActivity and toggle all six spinners
  together (all values come from one API call so they load in sync)

https://claude.ai/code/session_01HXPjBsogsJVRwCiekDGkJX

1 files changed, 60 insertions, 0 deletions

diff --git a/android-app/app/src/main/res/layout/layout_instruments_sheet.xml b/android-app/app/src/main/res/layout/layout_instruments_sheet.xml
index 03cefb7..edf0928 100644
--- a/android-app/app/src/main/res/layout/layout_instruments_sheet.xml
+++ b/android-app/app/src/main/res/layout/layout_instruments_sheet.xml
@@ -64,6 +64,16 @@
                     android:layout_marginStart="3dp"
                     android:layout_marginBottom="3dp"
                     android:layout_gravity="bottom" />
+                <ProgressBar
+                    android:id="@+id/spinner_tws"
+                    style="?android:attr/progressBarStyleSmall"
+                    android:layout_width="10dp"
+                    android:layout_height="10dp"
+                    android:indeterminate="true"
+                    android:visibility="gone"
+                    android:alpha="0.5"
+                    android:indeterminateTint="?attr/colorOnSurfaceVariant"
+                    android:layout_marginStart="4dp" />
             </LinearLayout>
             <TextView
                 android:id="@+id/bearing_tws"
@@ -96,6 +106,16 @@
                     style="@style/InstrumentPrimaryValue"
                     tools:text="18" />
                 <TextView android:id="@+id/unit_temp" style="@style/InstrumentUnit" android:text="°F" />
+                <ProgressBar
+                    android:id="@+id/spinner_temp"
+                    style="?android:attr/progressBarStyleSmall"
+                    android:layout_width="10dp"
+                    android:layout_height="10dp"
+                    android:indeterminate="true"
+                    android:visibility="gone"
+                    android:alpha="0.5"
+                    android:indeterminateTint="?attr/colorOnSurfaceVariant"
+                    android:layout_marginStart="4dp" />
             </LinearLayout>
         </LinearLayout>
 
@@ -124,6 +144,16 @@
                     style="@style/InstrumentPrimaryValue"
                     tools:text="1013" />
                 <TextView android:id="@+id/unit_baro" style="@style/InstrumentUnit" android:text="hPa" />
+                <ProgressBar
+                    android:id="@+id/spinner_baro"
+                    style="?android:attr/progressBarStyleSmall"
+                    android:layout_width="10dp"
+                    android:layout_height="10dp"
+                    android:indeterminate="true"
+                    android:visibility="gone"
+                    android:alpha="0.5"
+                    android:indeterminateTint="?attr/colorOnSurfaceVariant"
+                    android:layout_marginStart="4dp" />
             </LinearLayout>
         </LinearLayout>
 
@@ -176,6 +206,16 @@
                     style="@style/ForecastValue"
                     tools:text="0.8" />
                 <TextView android:id="@+id/unit_curr_spd" style="@style/ForecastUnit" android:text="kt" />
+                <ProgressBar
+                    android:id="@+id/spinner_curr"
+                    style="?android:attr/progressBarStyleSmall"
+                    android:layout_width="10dp"
+                    android:layout_height="10dp"
+                    android:indeterminate="true"
+                    android:visibility="gone"
+                    android:alpha="0.5"
+                    android:indeterminateTint="#5B9EC2"
+                    android:layout_marginStart="4dp" />
             </LinearLayout>
             <LinearLayout
                 android:layout_width="wrap_content"
@@ -215,6 +255,16 @@
                     style="@style/ForecastValue"
                     tools:text="3.5" />
                 <TextView android:id="@+id/unit_wave_ht" style="@style/ForecastUnit" android:text="ft" />
+                <ProgressBar
+                    android:id="@+id/spinner_waves"
+                    style="?android:attr/progressBarStyleSmall"
+                    android:layout_width="10dp"
+                    android:layout_height="10dp"
+                    android:indeterminate="true"
+                    android:visibility="gone"
+                    android:alpha="0.5"
+                    android:indeterminateTint="#5B9EC2"
+                    android:layout_marginStart="4dp" />
             </LinearLayout>
             <LinearLayout
                 android:layout_width="wrap_content"
@@ -254,6 +304,16 @@
                     style="@style/ForecastValue"
                     tools:text="5.2" />
                 <TextView android:id="@+id/unit_swell_ht" style="@style/ForecastUnit" android:text="ft" />
+                <ProgressBar
+                    android:id="@+id/spinner_swell"
+                    style="?android:attr/progressBarStyleSmall"
+                    android:layout_width="10dp"
+                    android:layout_height="10dp"
+                    android:indeterminate="true"
+                    android:visibility="gone"
+                    android:alpha="0.5"
+                    android:indeterminateTint="#5B9EC2"
+                    android:layout_marginStart="4dp" />
             </LinearLayout>
             <LinearLayout
                 android:layout_width="wrap_content"