fix: improve read-loop detection — consecutive-only, correct thresholds, fix bugs

Follow-up to PR #705 (merged from 0xbyt4). Addresses several issues:

1. CONSECUTIVE-ONLY TRACKING: Redesigned the read/search tracker to only
   warn/block on truly consecutive identical calls. Any other tool call
   in between (write, patch, terminal, etc.) resets the counter via
   notify_other_tool_call(), called from handle_function_call() in
   model_tools.py. This prevents false blocks in read→edit→verify flows.

2. THRESHOLD ADJUSTMENT: Warn on 3rd consecutive (was 2nd), block on
   4th+ consecutive (was 3rd+). Gives the model more room before
   intervening.

3. TUPLE UNPACKING BUG: Fixed get_read_files_summary() which crashed on
   search keys (5-tuple) when trying to unpack as 3-tuple. Now uses a
   separate read_history set that only tracks file reads.

4. WEB_EXTRACT DOCSTRING: Reverted incorrect removal of 'title' from
   web_extract return docs in code_execution_tool.py — the field IS
   returned by web_tools.py.

5. TESTS: Rewrote test_read_loop_detection.py (35 tests) to cover
   consecutive-only behavior, notify_other_tool_call, interleaved
   read/search, and summary-unaffected-by-searches.

model_tools.py

@@ -284,6 +284,16 @@ def handle_function_call(
     Returns:
         Function result as a JSON string.
     """
+    # Notify the read-loop tracker when a non-read/search tool runs,
+    # so the *consecutive* counter resets (reads after other work are fine).
+    _READ_SEARCH_TOOLS = {"read_file", "search_files"}
+    if function_name not in _READ_SEARCH_TOOLS:
+        try:
+            from tools.file_tools import notify_other_tool_call
+            notify_other_tool_call(task_id or "default")
+        except Exception:
+            pass  # file_tools may not be loaded yet
+
     try:
         if function_name in _AGENT_LOOP_TOOLS:
             return json.dumps({"error": f"{function_name} must be handled by the agent loop"})