Write down the UI polish noticed while cleaning up

One item so far: the session header's status sits tight against the right
edge while Back looks roomier, because the row's 8dp padding is measured
against a TextButton whose touch target is wider than its text. Not a
defect and not urgent, but the kind of thing that gets re-noticed and
re-diagnosed every few months unless it is written down once.

PLAN.md rather than a new file, since that is where this project's
decisions live, and this is a decision to defer rather than a bug to
track.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017xn8nHw1tw1R6PtiY1eEtw

PLAN.md

@@ -447,6 +447,19 @@ connectivity/lifecycle. The app keeps no persistent transcript store — the
 backend's transcript is the source of truth; the app caches only for the
 screen it's showing.
 
+### Deferred polish
+
+Noticed and deliberately not fixed yet, so they are not re-found from
+scratch. None is a defect; each is a decision waiting for the app to have
+been used enough to say which way.
+
+- **The session screen's header is lopsided.** The row is `padding(
+  horizontal = 8.dp)`, so the status on the right sits exactly 8dp from the
+  edge while "Back" on the left is a `TextButton` whose touch target is
+  wider than its text — the same 8dp reads as more. It is the "align the
+  mark, not the box" case: either align the button's content or size the
+  button to what it draws, rather than nudging with a hardcoded offset.
+
 ## Compaction: options explored
 
 Context: raw llama-server has no conversation memory management; the context