config: example block for cfg.memory.auto_summarize_on_quit (#102)

Documents the new opt-in keys (auto_summarize_on_quit,
min_turns_for_summary, summary_model) inline with the existing
Phase 4 memory block. Notes that the older summarizer_model key
is still honored for back-compat.

Config-only commit; no behavior change.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

config.lua

@@ -210,6 +210,18 @@ return {
     --     -- speed; "deep" or "cloud" for better extraction quality
     --     -- (cloud may have variable cost per session).
     --     summarizer_model = "fast",
+    --
+    --     -- #102: auto-summarize the session into memory.jsonl on :q.
+    --     -- When true, shutdown_session runs the same distill flow as
+    --     -- `:memory summarize`, non-interactively, and auto-adds the
+    --     -- parsed candidates. Silent no-op for trivial sessions (turn
+    --     -- count < min_turns_for_summary, default 5). pcall'd so a
+    --     -- broker failure never blocks :q.
+    --     auto_summarize_on_quit = true,
+    --     min_turns_for_summary  = 5,
+    --     summary_model          = "fast",  -- new alias; summarizer_model
+    --                                       -- above is still honored for
+    --                                       -- back-compat.
     -- },
 
     -- Phase 5 (docs/PHASE5.md): multi-model routing + cloud fallback +