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/MainScreen.kt

@@ -29,12 +29,10 @@ import androidx.lifecycle.repeatOnLifecycle
  * The app's root: one title, and four views of the backend behind it.
  *
  * These were four screens reached by four words in a row under the title, and the row was already
- * full -- the comment it replaced recorded that a fifth would have to go somewhere else. Tabs say
- * the same thing in less space and say one more thing besides: that these are places to be rather
- * than errands to run. Sessions, the machine's importable history, the models on it and the
- * machines themselves are all *the same backend*, looked at four ways, and none of them is a step
- * down from another. Settings still is a step down, which is why it stays a pushed screen and keeps
- * its own Back.
+ * full. Tabs say the same thing in less space and say one more thing besides: that these are places
+ * to be rather than errands to run. Sessions, the machine's importable history, the models on it
+ * and the machines themselves are all *the same backend*, looked at four ways, and none is a step
+ * down from another. Settings still is, which is why it stays a pushed screen with its own Back.
  */
 private enum class MainTab(val label: String) {
     Sessions("Sessions"),
@@ -61,17 +59,12 @@ fun MainScreen(
     //
     // What these four draw is a snapshot of a backend they are not connected to, so it is only as
     // fresh as the last answer -- and a *failed* answer is the one that outstays its welcome. A
-    // phone that was away while the tunnel was down, or that fetched before the network came up,
-    // came back to "Couldn't reach the server" sitting at the top of a list the server would now
-    // answer for perfectly well, and nothing took it off until somebody pressed Refresh. A stale
-    // failure is worse than a stale list: it is a claim about right now.
+    // phone that was away while the tunnel was down came back to "Couldn't reach the server"
+    // sitting at the top of a list the server would now answer for perfectly well. A stale failure
+    // is worse than a stale list: it is a claim about right now.
     //
     // Through the same token the Refresh button uses, so this is one instruction the tabs already
-    // understand rather than a second path into each of them -- which is also what makes it cover
-    // all four rather than the one the report came from.
-    //
-    // Not on the first entry: the tab composing already asks, and bumping here would make every
-    // cold start fetch twice.
+    // understand. Not on the first entry: the tab composing already asks.
     val lifecycleOwner = LocalLifecycleOwner.current
     LaunchedEffect(lifecycleOwner) {
         var opening = true
@@ -81,9 +74,8 @@ fun MainScreen(
         }
     }
 
-    // A tab the app put over the list has to step back to it rather than fall through to the
-    // system default, which closes the app -- that reads as a crash to somebody who only meant to
-    // get back to their sessions. Nested inside AppRoot's handler, so it wins while it is enabled.
+    // A tab the app put over the list has to step back to it rather than fall through to the system
+    // default, which closes the app. Nested inside AppRoot's handler, so it wins while enabled.
     BackHandler(enabled = tab != MainTab.Sessions) { tab = MainTab.Sessions }
 
     Column(Modifier.fillMaxSize()) {
@@ -98,20 +90,18 @@ fun MainScreen(
             )
             // Glyphs rather than the words they replaced: neither ever changes, both are read
             // faster than they are spelled, and together they take the width that let the title
-            // keep its own line. They sit on the title's row because they act on the whole
-            // screen -- everything below this row is one tab's business, and a control belongs
-            // with the thing it acts on.
-            // Flush against each other: a glyph button carries its own padding, so two of them
-            // side by side already have two rings between their marks and one ring plus this
-            // row's padding to the screen edge.
+            // keep its own line. They sit on the title's row because they act on the whole screen.
+            //
+            // Flush against each other: a glyph button carries its own padding, so two side by side
+            // already have two rings between their marks.
             Row {
                 GlyphButton(REFRESH_GLYPH, "Refresh", { refreshToken++ })
                 GlyphButton(SETTINGS_GLYPH, "Settings", onSettings)
             }
         }
-        // What is waiting to be attached, and what to do about it. Said here because the list
-        // below is where the choice is made, and a share that arrived with nothing on screen
-        // saying so would read as a tap that did nothing.
+        // What is waiting to be attached, and what to do about it. Said here because the list below
+        // is where the choice is made, and a share that arrived with nothing on screen saying so
+        // would read as a tap that did nothing.
         share?.let {
             Text(
                 it.summary() + " -- open the session it belongs in.",
@@ -127,8 +117,8 @@ fun MainScreen(
                         .padding(12.dp),
             )
         }
-        // Primary rather than the plain TabRow, which is deprecated in favour of the two that
-        // say where they sit: these are the app's top-level destinations.
+        // Primary rather than the plain TabRow, which is deprecated in favour of the two that say
+        // where they sit: these are the app's top-level destinations.
         PrimaryTabRow(selectedTabIndex = tab.ordinal) {
             MainTab.entries.forEach { entry ->
                 Tab(
@@ -139,10 +129,9 @@ fun MainScreen(
             }
         }
 
-        // Refreshing means "ask again about what I am looking at", so the button feeds the tab
-        // that is showing. The token from above means something else already changed what these
-        // show; the two are the same instruction to the tab below, so they are summed rather than
-        // tracked apart -- either one moving moves the sum, which is all a tab watches.
+        // Refreshing means "ask again about what I am looking at", so the button feeds the tab that
+        // is showing. The token from above means something else already changed what these show;
+        // the two are the same instruction, so they are summed rather than tracked apart.
         val token = reloadToken + refreshToken
         when (tab) {
             MainTab.Sessions ->