Thin the app's comments

The same pass the server had, on the Kotlin side: comments restating what
the code says are gone, and the ones recording a measurement, a constraint
or an incident are kept but cut to a few lines each. 6540 comment lines to
5674, and 920 lines off the app.

Two doc comments had drifted onto the item above the one they describe --
`contextAfter`'s onto `sessionWorking` in Events.kt, and `UsageMonitor`'s
equivalent on the server was fixed in the previous commit. Each is back on
its own item, which is the only non-comment line this diff moves.

The comments are reflowed to the column limit at their own indentation:
several were written wide, and ktfmt re-wrapped them into lines holding a
single orphan word. `/tmp` script, not kept -- ktfmt is idempotent over the
result, which is the check.

Left alone deliberately: this codebase's remaining comment density is high
because the comments carry things the code cannot say -- what a null means,
what a number was measured against, which bug a guard exists for. Of the
238 one-line doc comments in the app, five were pure restatement of the
name and were removed; the rest each say something the signature does not.

ktfmtFormat, compileDebugKotlin, lintDebug and testDebugUnitTest pass;
cargo test (127), clippy --all-targets and fmt still clean.

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

app/androidApp/src/main/kotlin/com/example/aiapp/Bubble.kt

@@ -8,18 +8,16 @@ import androidx.compose.ui.Modifier
 import androidx.compose.ui.graphics.Shape
 import androidx.compose.ui.unit.dp
 
-// The composer's row of settings and pickers, and the menus they open. One file because the
-// outline and the corner are one appearance: a control shaped like this opens a surface shaped
-// like this, and a reader learns the pair once.
+// The composer's row of settings and pickers, and the menus they open. One file because the outline
+// and the corner are one appearance: a control shaped like this opens a surface shaped like this.
 
 /**
  * A bordered pill: a control that can be seen without being pressed.
  *
  * The composer's row -- attach, model, permission mode -- was text buttons, which draw nothing at
- * all until they are touched. Three bare words sitting under the message field read as a caption
- * about the field rather than as three things to press, and the only way to find out otherwise was
- * to press one. The outline says "control" without the weight of a filled button, which is reserved
- * here for the two that act on the session (send, and start/stop).
+ * all until they are touched. Three bare words under the message field read as a caption about the
+ * field rather than as three things to press. The outline says "control" without the weight of a
+ * filled button, which is reserved for the two that act on the session.
  */
 @Composable
 fun BubbleButton(
@@ -32,8 +30,8 @@ fun BubbleButton(
         onClick = onClick,
         enabled = enabled,
         shape = BubbleShape,
-        // A text button's padding rather than a filled button's 24dp: these sit three across
-        // under the message field, and the wider padding is what decides whether the row fits.
+        // A text button's padding rather than a filled button's 24dp: these sit three across under
+        // the message field, and the wider padding is what decides whether the row fits.
         contentPadding = ButtonDefaults.TextButtonContentPadding,
         modifier = modifier,
     ) {
@@ -48,7 +46,6 @@ val BubbleShape: Shape = RoundedCornerShape(percent = 50)
  * The corner on a menu one of these opens.
  *
  * A radius rather than [BubbleShape]'s half-height: a menu is as tall as its options, and rounding
- * ends that tall would bow its sides. This is the roundest corner that still leaves a straight edge
- * beside a one-line option, which is the shortest menu here.
+ * ends that tall would bow its sides.
  */
 val BubbleMenuShape: Shape = RoundedCornerShape(20.dp)