idle-draft: clear attempts on success so forced redos start fresh

Claude-Session: https://claude.ai/code/session_01YQDoWNM7XPPii28khFWoMc

scripts/idle-draft

@@ -1096,11 +1096,30 @@ def log_gates(repo: Path, gates: dict, credential_ok: dict) -> None:
 
 
 def apply_success_state(state: dict, candidate: dict) -> None:
-    # Successful dispatch doesn't itself set a human gate; nothing to flip here.
-    # (human_edit_done / research_sampled / approved are human-only via `mark`.)
-    # Present for symmetry with apply_failure_state and as the extension point
-    # if a future work type needs to record something on success.
-    return
+    """On success, clear any failed-attempt history for this (item, work_type).
+    Without this, a success following one or more content failures leaves
+    attempts[work_type] at its prior nonzero value; if a human later deletes
+    the produced file to force a redo, the item would start already one
+    content failure away from `blocked` instead of fresh. Pruning (rather
+    than zeroing) the key/subkey keeps state minimal and matches how
+    get_item_state()/validate_state() already treat an absent attempts entry
+    as equivalent to zero -- nothing else (human_edit_done / research_sampled
+    / approved) is a success-path concern; those are human-only via `mark`."""
+    if candidate["kind"] != "item":
+        return
+    key = candidate["item_key"]
+    work_type = candidate["work_type"]
+    if work_type not in ALLOWED_ATTEMPT_WORK_TYPES:
+        return
+    entry = state.get("items", {}).get(key)
+    if entry is None:
+        return
+    attempts = entry.get("attempts")
+    if not attempts or work_type not in attempts:
+        return
+    del attempts[work_type]
+    if not attempts:
+        del entry["attempts"]
 
 
 def apply_failure_state(state: dict, candidate: dict, max_attempts: int) -> str | None: