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/RawBlock.kt

@@ -16,20 +16,17 @@ import androidx.compose.ui.unit.dp
  *
  * A composable rather than a modifier repeated at each site, because the inset is part of it --
  * monospace text drawn hard against the edge of a tinted block reads as a clipping fault, and three
- * copies of "clip, fill, pad" drift apart the first time one of them is adjusted.
+ * copies of "clip, fill, pad" drift apart the first time one is adjusted.
  *
- * The colour is [rawSurface], which is also what a code block inside a reply is given; that is the
- * point of having one name for it. Markdown's blocks are painted by the renderer rather than by
- * this, since it draws its own, but they are the same colour on purpose.
+ * The colour is [rawSurface], which is also what a code block inside a reply is given.
  */
 @Composable
 fun RawBlock(modifier: Modifier = Modifier, content: @Composable ColumnScope.() -> Unit) {
     Column(
         modifier
             .fillMaxWidth()
-            // Smaller than a card's radius, and deliberately: this sits *inside* one, and a
-            // rounded rectangle drawn at the same radius as the rounded rectangle behind it reads
-            // as a misprint rather than as nesting.
+            // Smaller than a card's radius, and deliberately: this sits *inside* one, and a rounded
+            // rectangle drawn at the same radius as the one behind it reads as a misprint.
             .clip(MaterialTheme.shapes.extraSmall)
             .background(rawSurface)
             .padding(horizontal = 8.dp, vertical = 6.dp),