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/PendingAttachments.kt

@@ -34,13 +34,10 @@ import androidx.compose.ui.unit.sp
  * What is about to be sent, directly above the box it will be sent from.
  *
  * The count on the "+" button was the whole of what said an image was attached, so the only way to
- * find out *which* image was to send it. A control belongs with the thing it acts on, and what
- * these are attached to is the message being typed -- which is why they sit here rather than
- * anywhere else on the screen.
+ * find out *which* image was to send it. A control belongs with the thing it acts on.
  *
  * Scrolls sideways rather than wrapping or shrinking: the row keeps one thumbnail size whatever is
- * in it, so four attachments look like four of the same thing rather than four smaller ones. A file
- * is a tile of the same height carrying its name, since a name is all there is to show of it.
+ * in it, so four attachments look like four of the same thing rather than four smaller ones.
  */
 @Composable
 fun PendingAttachments(
@@ -67,8 +64,7 @@ fun PendingAttachments(
  *
  * Removal is here because there is nowhere else it could be: an image picked by mistake could
  * otherwise only be dealt with by sending it. The whole thumbnail is the target rather than a
- * corner cross -- a cross small enough to sit on a 64dp square is smaller than a fingertip -- and
- * the label is what says so, since nothing about the picture does.
+ * corner cross -- a cross small enough to sit on a 64dp square is smaller than a fingertip.
  */
 @Composable
 private fun PendingThumbnail(
@@ -84,8 +80,7 @@ private fun PendingThumbnail(
             .clip(shape)
             // An outline as well as a fill. Most of what gets attached here is a screenshot of a
             // dark app, and cropped to a square its middle is often near-black -- against this
-            // background the tile then had no edge at all, and the only thing saying an image was
-            // attached was the cross drawn on top of nothing.
+            // background the tile then had no edge at all.
             .border(1.dp, MaterialTheme.colorScheme.outlineVariant, shape)
             // Behind the picture as well as under a missing one, so the tile is a tile before
             // anything has arrived to fill it.
@@ -105,9 +100,9 @@ private fun PendingThumbnail(
                         color = MaterialTheme.colorScheme.onSurfaceVariant,
                     )
                 } else {
-                    // A spinner, as the transcript's images have: one appearance for "a picture
-                    // is on its way", learned once. An ellipsis had to be read as a spinner that
-                    // was not moving.
+                    // A spinner, as the transcript's images have: one appearance for "a picture is
+                    // on its way", learned once. An ellipsis had to be read as a spinner not
+                    // moving.
                     CircularProgressIndicator(Modifier.size(20.dp), strokeWidth = 2.dp)
                 }
             else ->
@@ -118,14 +113,12 @@ private fun PendingThumbnail(
                     modifier = Modifier.size(THUMBNAIL),
                 )
         }
-        // The whole square removes it, and this only says so. A cross small enough to sit in
-        // the corner of a 64dp thumbnail is smaller than a fingertip, so making it the target
-        // would be a control drawn at a size nobody can hit.
+        // The whole square removes it, and this only says so. A cross small enough to sit in the
+        // corner of a 64dp thumbnail is smaller than a fingertip.
         //
         // The disc is sized here and the mark centred inside it, rather than the glyph being
-        // aligned directly: a glyph's box is wider than the cross it draws, so aligning the box
-        // to the corner hung the visible mark over the edge and put its backing somewhere the
-        // eye reads as a second, misplaced square.
+        // aligned directly: a glyph's box is wider than the cross it draws, so aligning the box to
+        // the corner hung the visible mark over the edge.
         Box(
             Modifier.align(Alignment.TopEnd)
                 .padding(2.dp)