When agentic_loop suspends for an MCP bridge tool it returns a
{"tool_pending":true,...} envelope with no "reply" key. Without an
explicit check, json_get(loop_result, "reply") returns "" and the
function emitted {"response":"","cgi_id":"..."} — a silent empty
response indistinguishable from a successful LLM turn with no content.
Two guards added after the existing error check:
1. tool_pending passthrough: if the loop suspended, return the pending
envelope directly so callers (dharma room orchestrators) can
distinguish suspension from failure and route to the approve flow.
2. Empty-reply guard: if final_text is empty after the pending check,
return an explicit {"error":"no response",...} envelope instead of
silently succeeding with an empty response field.
Also adds tests/test_agentic_tools.el:
- agentic_tools_all() includes all literal tool names and web_search
- connector_tools_json() returns valid JSON when bridge is down (graceful degradation)
- tool_pending envelope detection patterns (the is_pending logic)
- json_get(pending_envelope, "reply") returns "" confirming the empty-reply
guard is load-bearing (pure string/JSON, no LLM or network required)
