feat(agent): cross-char search_items tool + bump timeouts

Adds an MCP tool wrapping the inventory-service /search/items endpoint
with include_all_characters=true, so questions like 'find me a bracelet
with Legendary Acid Ward on any unequipped char' resolve in ONE tool call
instead of looping get_inventory over 60+ chars (which timed out at 120s).

- agent/tools.py: search_items_global wrapper
- agent/mcp_overlord.py: register new tool with detailed schema doc
- agent/claude_wrapper.py: include in --allowed-tools whitelist;
  bump timeout 120s -> 240s
- nginx/overlord.conf: bump /api/agent/ proxy timeout 180s -> 300s
- CLAUDE.md: brief Claude to USE search_items for cross-char searches

agent/claude_wrapper.py

@@ -27,7 +27,7 @@ CLAUDE_CWD = os.getenv("CLAUDE_CWD", "/home/erik/MosswartOverlord")
 # Hard cap on how long a single agent turn may take. Claude Code can spin a
 # while when chaining many tool calls; we don't want to leave a zombie
 # subprocess if something gets stuck.
-CLAUDE_TIMEOUT_S = int(os.getenv("CLAUDE_TIMEOUT_S", "120"))
+CLAUDE_TIMEOUT_S = int(os.getenv("CLAUDE_TIMEOUT_S", "240"))
 
 
 @dataclass
@@ -82,6 +82,7 @@ async def ask_claude(message: str, session_id: str) -> ClaudeResult:
             "mcp__overlord__get_player_state",
             "mcp__overlord__get_inventory",
             "mcp__overlord__get_inventory_search",
+            "mcp__overlord__search_items",
             "mcp__overlord__get_combat_stats",
             "mcp__overlord__get_equipment_cantrips",
             "mcp__overlord__get_quest_status",