feat(delegate): cross-agent file state coordination for concurrent subagents (#13718)

* feat(models): hide OpenRouter models that don't advertise tool support

Port from Kilo-Org/kilocode#9068.

hermes-agent is tool-calling-first — every provider path assumes the
model can invoke tools. Models whose OpenRouter supported_parameters
doesn't include 'tools' (e.g. image-only or completion-only models)
cannot be driven by the agent loop and fail at the first tool call.

Filter them out of fetch_openrouter_models() so they never appear in
the model picker (`hermes model`, setup wizard, /model slash command).

Permissive when the field is missing — OpenRouter-compatible gateways
(Nous Portal, private mirrors, older snapshots) don't always populate
supported_parameters. Treat missing as 'unknown → allow' rather than
silently emptying the picker on those gateways. Only hide models
whose supported_parameters is an explicit list that omits tools.

Tests cover: tools present → kept, tools absent → dropped, field
missing → kept, malformed non-list → kept, non-dict item → kept,
empty list → dropped.

* feat(delegate): cross-agent file state coordination for concurrent subagents

Prevents mangled edits when concurrent subagents touch the same file
(same process, same filesystem — the mangle scenario from #11215).

Three layers, all opt-out via HERMES_DISABLE_FILE_STATE_GUARD=1:

1. FileStateRegistry (tools/file_state.py) — process-wide singleton
   tracking per-agent read stamps and the last writer globally.
   check_stale() names the sibling subagent in the warning when a
   non-owning agent wrote after this agent's last read.

2. Per-path threading.Lock wrapped around the read-modify-write
   region in write_file_tool and patch_tool. Concurrent siblings on
   the same path serialize; different paths stay fully parallel.
   V4A multi-file patches lock in sorted path order (deadlock-free).

3. Delegate-completion reminder in tools/delegate_tool.py: after a
   subagent returns, writes_since(parent, child_start, parent_reads)
   appends '[NOTE: subagent modified files the parent previously
   read — re-read before editing: ...]' to entry.summary when the
   child touched anything the parent had already seen.

Complements (does not replace) the existing path-overlap check in
run_agent._should_parallelize_tool_batch — batch check prevents
same-file parallel dispatch within one agent's turn (cheap prevention,
zero API cost), registry catches cross-subagent and cross-turn
staleness at write time (detection).

Behavior is warning-only, not hard-failing — matches existing project
style. Errors surface naturally: sibling writes often invalidate the
old_string in patch operations, which already errors cleanly.

Tests: tests/tools/test_file_state_registry.py — 16 tests covering
registry state transitions, per-path locking, per-path-not-global
locking, writes_since filtering, kill switch, and end-to-end
integration through the real read_file/write_file/patch handlers.

tools/delegate_tool.py

@@ -27,6 +27,7 @@ from concurrent.futures import ThreadPoolExecutor, as_completed
 from typing import Any, Dict, List, Optional
 
 from toolsets import TOOLSETS
+from tools import file_state
 from utils import base_url_hostname
 
 
@@ -728,7 +729,22 @@ def _run_single_child(
             except Exception as e:
                 logger.debug("Progress callback start failed: %s", e)
 
-        result = child.run_conversation(user_message=goal)
+        # File-state coordination: generate a stable child task_id so the
+        # file_state registry can attribute writes back to this subagent,
+        # and snapshot the parent's read set at launch time.  After the
+        # child returns we compare to detect "sibling modified files the
+        # parent previously read" and surface it as a reminder on the
+        # returned summary.
+        import uuid as _uuid
+        child_task_id = f"subagent-{task_index}-{_uuid.uuid4().hex[:8]}"
+        parent_task_id = getattr(parent_agent, "_current_task_id", None)
+        wall_start = time.time()
+        parent_reads_snapshot = (
+            list(file_state.known_reads(parent_task_id))
+            if parent_task_id else []
+        )
+
+        result = child.run_conversation(user_message=goal, task_id=child_task_id)
 
         # Flush any remaining batched progress to gateway
         if child_progress_cb and hasattr(child_progress_cb, '_flush'):
@@ -826,6 +842,36 @@ def _run_single_child(
         if status == "failed":
             entry["error"] = result.get("error", "Subagent did not produce a response.")
 
+        # Cross-agent file-state reminder.  If this subagent wrote any
+        # files the parent had already read, surface it so the parent
+        # knows to re-read before editing — the scenario that motivated
+        # the registry.  We check writes by ANY non-parent task_id (not
+        # just this child's), which also covers transitive writes from
+        # nested orchestrator→worker chains.
+        try:
+            if parent_task_id and parent_reads_snapshot:
+                sibling_writes = file_state.writes_since(
+                    parent_task_id, wall_start, parent_reads_snapshot
+                )
+                if sibling_writes:
+                    mod_paths = sorted(
+                        {p for paths in sibling_writes.values() for p in paths}
+                    )
+                    if mod_paths:
+                        reminder = (
+                            "\n\n[NOTE: subagent modified files the parent "
+                            "previously read — re-read before editing: "
+                            + ", ".join(mod_paths[:8])
+                            + (f" (+{len(mod_paths) - 8} more)" if len(mod_paths) > 8 else "")
+                            + "]"
+                        )
+                        if entry.get("summary"):
+                            entry["summary"] = entry["summary"] + reminder
+                        else:
+                            entry["stale_paths"] = mod_paths
+        except Exception:
+            logger.debug("file_state sibling-write check failed", exc_info=True)
+
         if child_progress_cb:
             try:
                 child_progress_cb(