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/FilesScreen.kt

@@ -45,7 +45,7 @@ import kotlinx.coroutines.withContext
  * Which machine's files to show, and where to start.
  *
  * A **setup**, not a session: a filesystem is a property of a machine, and a session only says
- * where it was working. That is what makes a second way in -- from the setups tab, say -- one more
+ * where it was working. That is what makes a second way in -- from the setups tab -- one more
  * caller rather than any new code here.
  */
 data class FilesTarget(val setup: String, val setupName: String, val start: String)
@@ -61,13 +61,13 @@ private sealed class Spot(val path: String) {
  * The files on the machine a session runs on: browse them, read one, change one.
  *
  * Drawn **over** the session rather than instead of it (see [AppRoot]), so its event stream keeps
- * flowing, its draft and scroll position stay where they were, and coming back from a file costs
- * nothing. Back steps one level inside here -- editor to viewer, viewer to the directory it came
- * from, directory to the one above it -- and only closes from where it opened.
+ * flowing and coming back from a file costs nothing. Back steps one level inside here -- editor to
+ * viewer, viewer to the directory it came from, directory to the one above -- and only closes from
+ * where it opened.
  *
- * Every directory that has been visited is kept for as long as this is open, so stepping back is
- * instant; the refresh glyph is how a directory gets asked again on purpose, and creating something
- * refetches the directory it was created in, since that is the one thing that changed.
+ * Every directory that has been visited is kept for as long as this is open; the refresh glyph is
+ * how one gets asked again on purpose, and creating something refetches the directory it was
+ * created in.
  */
 @Composable
 fun FilesScreen(settings: ServerSettings, target: FilesTarget, onClose: () -> Unit) {
@@ -121,17 +121,16 @@ fun FilesScreen(settings: ServerSettings, target: FilesTarget, onClose: () -> Un
     Box(
         Modifier.fillMaxSize()
             .background(MaterialTheme.colorScheme.background)
-            // The session under this deliberately takes no keyboard inset (see SessionScreen's
-            // layout note), so the explorer adds its own -- otherwise the editor types under the
-            // keyboard.
+            // The session under this deliberately takes no keyboard inset, so the explorer adds its
+            // own -- otherwise the editor types under the keyboard.
             .imePadding()
     ) {
         Column(Modifier.fillMaxSize()) {
             when (val spot = here) {
                 is Spot.Dir -> {
                     val state = listings[spot.path] ?: LoadState.Loading
-                    // The resolved path once there is one: a directory opened as `~` is called
-                    // what it turned out to be, not what it was asked for.
+                    // The resolved path once there is one: a directory opened as `~` is called what
+                    // it turned out to be, not what it was asked for.
                     val at = (state as? LoadState.Loaded)?.value?.path ?: spot.path
                     FilesHeader(
                         title = baseName(at),
@@ -304,9 +303,8 @@ private fun ColumnScope.DirectoryBody(state: LoadState<Listing>, onOpen: (Spot)
  *
  * A symlink says so instead of giving a size, because the size a listing reports for one is the
  * length of the path it points at -- a number that looks exactly like a file size and is about
- * something else entirely. `other` covers a fifo, a device, and a link whose target is gone: the
- * row still appears, because a directory that hid what it held would be lying about being empty,
- * and the word is there because a colour cannot say "this is a different kind of thing".
+ * something else. `other` covers a fifo, a device, and a link whose target is gone: the row still
+ * appears, because a directory that hid what it held would be lying about being empty.
  */
 private fun trailingOf(entry: DirEntry): String? =
     when {
@@ -350,8 +348,7 @@ private fun EntryRow(glyph: String, name: String, trailing: String?, onClick: ()
  *
  * Its own composable so that everything about one file -- what came back, what has been typed, and
  * whether a save is out -- is remembered under that file's path and thrown away when the reader
- * moves to another. What is *not* here is edit mode itself: back has to know about it, and back
- * belongs to the screen.
+ * moves to another. What is *not* here is edit mode itself: back has to know about it.
  */
 @Composable
 private fun ColumnScope.DocPane(
@@ -423,8 +420,8 @@ private fun ColumnScope.DocPane(
                 onDirty(false)
                 onEditing(false)
             } catch (e: ApiException) {
-                // The one refusal that is a question rather than a message: somebody else's edit
-                // is on the machine, and which of the two survives is not this app's to decide.
+                // The one refusal that is a question rather than a message: somebody else's edit is
+                // on the machine, and which of the two survives is not this app's to decide.
                 if (e.status == 409) conflict = e.message ?: "It changed on the machine."
                 else saveError = e.message
             } finally {
@@ -467,10 +464,10 @@ private fun ColumnScope.DocPane(
         )
     }
 
-    // Why the pencil is off. A disabled control teaches what the thing can do, but it cannot say
-    // why it is disabled -- and a reader who cannot edit a file they can plainly read will
-    // otherwise conclude the app is broken. Said once, here, rather than waiting for a tap that a
-    // disabled button never receives.
+    // Why the pencil is off. A disabled control teaches what the thing can do but cannot say why it
+    // is disabled -- and a reader who cannot edit a file they can plainly read will otherwise
+    // conclude the app is broken. Said once, here, rather than waiting for a tap a disabled button
+    // never gets.
     if (loaded != null && !editable) {
         Text(
             "Too big to edit here (${humanSize(loaded.size)}; the limit is " +
@@ -687,6 +684,5 @@ internal fun baseName(path: String): String {
     return if (trimmed.isEmpty()) "/" else trimmed.substringAfterLast('/')
 }
 
-/** A resolved directory and a name in it, as one path. */
 internal fun join(directory: String, name: String): String =
     if (directory.endsWith("/")) "$directory$name" else "$directory/$name"