feat: add Gemini 3.7 Flash to Gemini CUA and HyperAgent

Accept gemini-3.7-flash on GeminiComputerUseLlm and HyperAgentLlm to match the API.

Co-authored-by: shri <shri@metlo.com>

Author: cursoragent

hyperbrowser/models/consts.py

@@ -62,6 +62,7 @@
     "claude-sonnet-4-6",
     "claude-sonnet-4-5",
     "gemini-2.5-flash",
+    "gemini-3.7-flash",
     "gemini-3-flash-preview",
 ]
 ClaudeComputerUseLlm = Literal[
@@ -87,6 +88,7 @@
     "gpt-5.4-mini",
 ]
 GeminiComputerUseLlm = Literal[
+    "gemini-3.7-flash",
     "gemini-3.6-flash",
     "gemini-3.5-flash",
     "gemini-3.5-flash-lite",