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/BusyItem.kt

@@ -26,20 +26,16 @@ import androidx.compose.ui.unit.dp
  * of the operation over it.
  *
  * One composable rather than a pattern each list repeats, because "this row is busy" has to look
- * the same in the import list and the session list or the appearance becomes a per-screen dialect
- * rather than something the reader learns once.
+ * the same in the import list and the session list or the appearance becomes a per-screen dialect.
  *
  * [label] names the operation and `null` means none is running. One parameter rather than a boolean
- * beside a string, which can disagree: there is no such thing as busy with nothing happening. It is
- * a *word* because a spinner alone cannot say which operation this is — deleting and importing are
- * different in kind, and losing a session to the wrong one is not recoverable by waiting.
+ * beside a string, which can disagree. It is a *word* because a spinner alone cannot say which
+ * operation this is -- deleting and importing are different in kind.
  *
  * It does **not** make the row inert; the caller disables its own click handling while it passes a
- * label. That was the other way round at first — an overlay consuming pointer events, so no caller
- * had to remember — and it swallowed the drag along with the tap, which meant a list could not be
- * scrolled while anything in it was busy. Consuming taps but not drags means re-deciding what a
- * gesture is above the components that already decide it; disabling the click is the platform's own
- * answer and leaves the scroll where it belongs.
+ * label. That was the other way round at first -- an overlay consuming pointer events -- and it
+ * swallowed the drag along with the tap, so a list could not be scrolled while anything in it was
+ * busy.
  */
 @Composable
 fun BusyItem(label: String?, content: @Composable () -> Unit) {
@@ -71,14 +67,12 @@ fun BusyItem(label: String?, content: @Composable () -> Unit) {
 /**
  * How an item looks while it is being acted on: darker, and nearly grey.
  *
- * Both, rather than either alone. Dimming by itself is what this app already used for a row on its
- * way out, and it is the same cue as a disabled control, so a busy row read as one more thing that
- * could not be tapped. Draining the colour is what says the row is *suspended* — the status word,
- * the accent on a warning and everything else that means something by its colour stop meaning it
- * for as long as the operation runs, which is exactly true: none of them is being kept up to date.
+ * Both, rather than either alone. Dimming by itself is the same cue as a disabled control, so a
+ * busy row read as one more thing that could not be tapped. Draining the colour is what says the
+ * row is *suspended* -- the status word and everything else that means something by its colour stop
+ * meaning it for as long as the operation runs, which is exactly true.
  *
- * Not all the way to grey. A row with no colour left is hard to find again in a list, and the
- * reader is watching this one.
+ * Not all the way to grey: a row with no colour left is hard to find again in a list.
  */
 private fun Modifier.busy(busy: Boolean): Modifier =
     if (!busy) this