feat: auto-delete old conversations, and stop a tool call that repeats (#15)

src/lib/constants.ts

@@ -16,8 +16,32 @@ export const STORAGE_SESSION_PREFIX = "lam.session.";
  * preamble the model had written was discarded, and the turn ended with a notice
  * about the limit rather than an answer. The closing round in `agent.ts` now
  * turns that into an answer, and this is the room it gets to gather first.
+ *
+ * A default rather than a ceiling: the Tool Call Limit preference overrides it,
+ * and "Unlimited" removes it entirely.
  */
-export const MAX_TOOL_ITERATIONS = 8;
+export const DEFAULT_MAX_TOOL_ROUNDS = 8;
+
+/**
+ * How many times one turn may ask for the exact same call before the loop gives
+ * up on it.
+ *
+ * A model stuck in a rut repeats itself with identical arguments, so the repeat
+ * is the signal: the third time it asks the same question it is not going to
+ * learn anything new, and the only thing a fourth round buys is another round.
+ * This is the backstop the rounds cap cannot be, because the cap can be set to
+ * Unlimited.
+ */
+export const MAX_REPEATED_TOOL_CALLS = 3;
+
+/**
+ * How long a snip must sit unreferenced before the orphan sweep collects it.
+ *
+ * Snips are written to disk before the chat view opens, and a capture the user
+ * never sends is stored nowhere. The wait is what keeps the sweep from deleting
+ * the file out from under a snip the user is still deciding what to ask about.
+ */
+export const SNIP_ORPHAN_GRACE_MS = 24 * 60 * 60 * 1000;
 
 /** Oldest sessions past this count are evicted, along with their storage keys. */
 export const MAX_SESSIONS = 100;