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/NerdIcons.kt

@@ -26,26 +26,21 @@ import androidx.compose.ui.unit.sp
  * set and kept in step by hand.
  *
  * This replaced a hand-drawn canvas gear, whose doc comment argued against icon fonts on the
- * grounds that a system font may not have the glyph and whoever gets the empty box instead is never
- * the person who wrote it. That objection is about *relying* on a system font, and it is exactly
- * right: the answer is not to avoid glyphs but to ship them. The font here is
- * `app/build-icon-font.sh`'s output -- seventeen glyphs, 2.8 KB, subset out of the 3 MB symbols
- * font and committed -- so the codepoints below are resolved by an asset in the APK and cannot come
- * back as tofu. Adding one means adding its codepoint in *both* places; a codepoint here that the
- * script did not subset is a glyph that silently isn't there.
+ * grounds that a system font may not have the glyph. That objection is about *relying* on a system
+ * font, and it is exactly right: the answer is not to avoid glyphs but to ship them. The font here
+ * is `app/build-icon-font.sh`'s output -- seventeen glyphs, 2.8 KB, subset out of the 3 MB symbols
+ * font and committed. Adding one means adding its codepoint in *both* places; a codepoint here that
+ * the script did not subset is a glyph that silently isn't there.
  *
  * The subset is the font's **Mono** face, where every glyph is exactly one em wide and one em tall.
- * That is what makes two icons the same size without either of them being given a size: the
- * proportional face's advances run from 0.46 em to 0.92 em, so a Send button and a Stop button side
- * by side came out visibly different widths, and matching them at the call site would have meant
- * one hardcoded measurement per pair. [GLYPH_SIZE] carries the cost.
+ * That is what makes two icons the same size without either being given a size: the proportional
+ * face's advances run from 0.46 em to 0.92 em, so a Send button and a Stop button side by side came
+ * out visibly different widths. [GLYPH_SIZE] carries the cost.
  *
  * The same arrangement as dev-updater, down to the cog and the refresh arrow being the same two
- * Material Design codepoints. Those two must not drift: an icon that means "settings" in one app
- * and something else in the other is the failure this is worth preventing. The script is copied
- * rather than shared because most of what looks like duplication is the `GLYPHS` list, which has to
- * differ -- the point of subsetting is to ship only the codepoints one app draws. All Material
- * Design bar one, so they read as one family; the exception is noted where it is declared.
+ * Material Design codepoints. Those two must not drift. The script is copied rather than shared
+ * because most of what looks like duplication is the `GLYPHS` list, which has to differ -- the
+ * point of subsetting is to ship only the codepoints one app draws.
  */
 val NerdIcons = FontFamily(Font(R.font.nerd_icons))
 
@@ -74,8 +69,7 @@ val STOP_GLYPH = glyph(0xF04DB)
  *
  * The pair with [STOP_GLYPH] and [PLAY_GLYPH] is the point: one button in the composer says what
  * pressing it now would do to the process, and the three marks are the three answers. An interrupt
- * ends a turn and nothing else -- the CLI is still there and still holds the conversation -- which
- * is a pause, not a stop, and drawing it as a square said otherwise.
+ * ends a turn and nothing else, which is a pause, not a stop.
  */
 val PAUSE_GLYPH = glyph(0xF03E4)
 
@@ -86,8 +80,8 @@ val PLAY_GLYPH = glyph(0xF040A)
  * `md-send_clock` -- the same paper plane with a clock on it: this message will wait its turn.
  *
  * The pair with [SEND_GLYPH] is the point. Sending during a turn queues the message rather than
- * starting one, and the two buttons have to be told apart at a glance -- one glyph doing both jobs
- * while looking identical would promise something immediate and do something that waits.
+ * starting one, and one glyph doing both jobs would promise something immediate and do something
+ * that waits.
  */
 val QUEUE_GLYPH = glyph(0xF1163)
 
@@ -104,8 +98,7 @@ val BELL_GLYPH = glyph(0xF009A)
  * `fa-line_chart` -- how much of the account's rate limits is gone.
  *
  * Font Awesome's rather than Material's, which is the one break in the family above: it was asked
- * for by name, and Material's chart glyphs are a bare line where this one has its axes, which is
- * what makes it read as a measurement rather than as a trend.
+ * for by name, and Material's chart glyphs are a bare line where this one has its axes.
  */
 val USAGE_GLYPH = glyph(0xF201)
 
@@ -121,9 +114,8 @@ val SPEED_GLYPH = glyph(0xF04C5)
  * `md-folder` -- the files on the machine this session runs on.
  *
  * The same codepoint dev-updater uses, and it must not drift from it, for the reason the cog and
- * the refresh arrow must not: a folder that meant something else in one of the two apps is exactly
- * the confusion sharing them prevents. Doubles as the mark on a directory row inside the explorer,
- * which is what makes the button say where it leads.
+ * the refresh arrow must not. Doubles as the mark on a directory row inside the explorer, which is
+ * what makes the button say where it leads.
  */
 val FOLDER_GLYPH = glyph(0xF024B)
 
@@ -148,10 +140,9 @@ val SAVE_GLYPH = glyph(0xF0193)
  * The size an icon draws at beside a line of text.
  *
  * 17 rather than the 20 it was while the font was the proportional face. A glyph there filled at
- * most 0.83 em of its point size and most filled a good deal less, so the number was standing in
- * for the headroom above the tallest one; in the Mono face every glyph fills its em exactly, and
- * keeping 20 would have made every icon in the app step up by a fifth for no reason anybody asked
- * for. This is what the largest of them already drew at.
+ * most 0.83 em of its point size, so the number was standing in for the headroom above the tallest
+ * one; in the Mono face every glyph fills its em exactly, and keeping 20 would have stepped every
+ * icon in the app up by a fifth.
  */
 private val GLYPH_SIZE = 17.sp
 
@@ -165,16 +156,14 @@ private val GLYPH_EXTENT = GLYPH_SIZE.value.dp
  *
  * The ring is the whole spacing rule. Every gap around a header icon comes out of it -- one ring to
  * the screen edge, two where a button meets its neighbour -- so nothing outside has to add a gap of
- * its own, and a mark cannot end up further from the button beside it than from the edge of the
- * screen. That is what it was: the box was the size of the mark (28dp) and the separation was
+ * its own. That is what it was: the box was the size of the mark (28dp) and the separation was
  * bolted on beside it, which left the two header icons 31dp apart and the outer one 14dp from the
- * edge, so a pair that acts on one screen read as two unrelated marks with one falling off it.
+ * edge.
  *
  * 48dp is the platform's minimum touch target, so the square is also the whole of what a finger has
- * to find. It is what the pressed-state ripple draws, too: at 28dp that circle was inscribed in the
- * mark's own corners, and beside a title it arrived at the first letter. And it is taller than any
- * header's text, which is what lets the button fill a header row rather than sit in the middle of
- * one -- the rows add no vertical padding of their own for the same reason they add no gap.
+ * to find, and what the pressed-state ripple draws: at 28dp that circle was inscribed in the mark's
+ * own corners and beside a title it arrived at the first letter. And it is taller than any header's
+ * text, which is what lets the button fill a header row rather than sit in the middle of one.
  */
 private val GLYPH_BUTTON_SIZE = 48.dp
 
@@ -182,11 +171,9 @@ private val GLYPH_BUTTON_SIZE = 48.dp
  * The ring itself, for putting something that is *not* a glyph button next to one -- a title beside
  * a back arrow.
  *
- * Two glyph buttons need nothing between them: each brings its own ring and the two add up, which
- * is why a row of them sets no spacing. Text brings none, so the second ring has to be asked for.
- * Without it the pressed-state circle, which fills the whole square, arrives at the first letter of
- * the title -- and the gap a reader sees between the mark and that title is then half the one
- * between the two marks at the other end of the same row.
+ * Two glyph buttons need nothing between them: each brings its own ring and the two add up. Text
+ * brings none, so the second ring has to be asked for -- without it the pressed-state circle
+ * arrives at the first letter of the title.
  */
 val GLYPH_BUTTON_MARGIN = (GLYPH_BUTTON_SIZE - GLYPH_EXTENT) / 2
 
@@ -195,8 +182,7 @@ val GLYPH_BUTTON_MARGIN = (GLYPH_BUTTON_SIZE - GLYPH_EXTENT) / 2
  *
  * Its own composable so that every icon button in the app is one size and one colour without each
  * caller saying so, and so the [label] none of them displays is still there for a screen reader --
- * which is all assistive technology has to go on, and also the answer to "what was that button for"
- * six months from now.
+ * which is also the answer to "what was that button for" six months from now.
  *
  * [enabled] is passed through rather than left to callers hiding the button: a control that comes
  * and goes makes its own absence the signal, and absence cannot say whether there was nothing to do
@@ -220,9 +206,8 @@ fun GlyphButton(
  * The same square, around a mark that is not a glyph.
  *
  * A [Chevron] is drawn rather than set in a font, and a pair of them used as buttons has to be the
- * size, spacing and touch target every other icon button on this app's headers already is -- so
- * this is [GlyphButton] with the mark left to the caller rather than a second set of measurements
- * beside it. The caller still owes it a [label]: nothing here draws a word.
+ * size, spacing and touch target every other icon button already is. The caller still owes it a
+ * [label]: nothing here draws a word.
  */
 @Composable
 fun MarkButton(
@@ -245,9 +230,7 @@ fun MarkButton(
  * The square a glyph button occupies, with a spinner in it instead of a mark.
  *
  * For a button whose work is under way. It takes the button's whole box rather than the mark's, so
- * swapping one for the other leaves everything in the row exactly where it was -- a control that
- * changed the width of its header while it worked would move its neighbours at the moment somebody
- * was pressing them.
+ * swapping one for the other leaves everything in the row exactly where it was.
  */
 @Composable
 fun GlyphSpinner(label: String, modifier: Modifier = Modifier) {
@@ -273,10 +256,9 @@ fun Glyph(
     size: TextUnit = GLYPH_SIZE,
 ) {
     // Line height of the point size, which for this font is the square the glyph draws in: its
-    // ascent and descent add up to exactly one em, and every glyph in the Mono face fills that em.
-    // Left to the inherited body style the line box was 24sp tall around a 17sp-wide mark, so a
-    // glyph took a seventh more vertical space than horizontal wherever one is drawn without a box
-    // around it -- and where there is a box, that leading is what its padding is measured through.
+    // ascent and descent add up to exactly one em. Left to the inherited body style the line box
+    // was 24sp tall around a 17sp-wide mark, so a glyph took a seventh more vertical space than
+    // horizontal.
     Text(
         glyph,
         fontFamily = NerdIcons,