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/CrashLog.kt

@@ -12,10 +12,9 @@ import java.util.Locale
  * The last crash, kept so the debug button can hand it over.
  *
  * The alternative is asking somebody to reproduce a crash with the phone plugged into a computer
- * and `logcat` running, which is the one thing nobody has set up at the moment it happens -- and a
- * crash report that arrives a day later, without the stack, is a guess. This costs one file write
- * on a process that is already dying, and it turns "it crashes when I open that chat" into the
- * frame it crashed in.
+ * and `logcat` running, which is the one thing nobody has set up at the moment it happens. This
+ * costs one file write on a process that is already dying, and it turns "it crashes when I open
+ * that chat" into the frame it crashed in.
  *
  * Kept until it is read rather than cleared on the next launch: the app restarts before anybody can
  * ask about it, so a log that lives for one session is a log that is never read.
@@ -26,8 +25,7 @@ private const val CRASH_FILE = "last-crash.txt"
  * How much of a stack is kept.
  *
  * This is pasted into a conversation, so it has a budget like any other output written for a
- * reader. The top of a stack is what identifies a crash and the bottom is framework plumbing, so
- * what gets cut is the part nobody reads.
+ * reader. The top of a stack is what identifies a crash and the bottom is framework plumbing.
  */
 private const val CRASH_LIMIT = 4000
 
@@ -35,8 +33,7 @@ private const val CRASH_LIMIT = 4000
  * Records uncaught exceptions, then lets the platform do what it was going to do.
  *
  * Chained rather than replacing: the default handler is what shows the "app has stopped" dialog and
- * ends the process, and an app that swallows that instead sits there in an unknown state. This only
- * adds a witness.
+ * ends the process, and an app that swallows that instead sits there in an unknown state.
  */
 fun installCrashLog(context: Context) {
     val app = context.applicationContext