address mara: drop CompactionMode, always checkpoint-then-compact

docs/turn-loop.md

@@ -517,12 +517,10 @@ ttl_seconds?, to?)`, `answer(id, answer)`.
   explicit `from: "graceful-stop"` message instead of an empty inbox.
   This unmissably directs the agent to flush durable state (`/state`
   files) and end the turn — the container exits when the turn completes.
-  This is a **single** wake: the graceful-stop turn *is* the checkpoint
-  (its prompt carries the full notes/CLAUDE.md/TODO.md flush guidance),
-  so the harness compacts directly afterwards if the context crossed the
-  watermark (`CompactionMode::CompactOnly`) rather than waking a second
-  dedicated checkpoint turn. Compacting before shutdown keeps a later
-  cold start cheap instead of re-uploading a huge transcript.
+  The graceful-stop turn takes the same post-turn compaction path as any
+  other turn: if the context crossed the watermark the harness runs a
+  notes-checkpoint turn and then `/compact`. Compacting before shutdown
+  keeps a later cold start cheap instead of re-uploading a huge transcript.
 - `ask` — surface a structured question to the operator (default) or
   a peer agent (`to: "<agent>"`). Non-blocking — returns a question
   id; the answer arrives as a `question_answered` system event in the