fix: set httpx read timeout for long-running commands and handle

non-JSON error responses
- Set per-request httpx timeout (command timeout + 10s buffer) in
  Commands.run() and AsyncCommands.run() for foreground exec calls,
  preventing HTTP read timeouts on long-running commands
- Raise WrennInternalError instead of raw httpx.HTTPStatusError when
  handle_response() encounters a non-JSON error body (e.g. 502 from
  a reverse proxy)

.gitignore

@@ -175,3 +175,6 @@ cython_debug/
 .pypirc
 
 CODE_EXECUTION.md
+
+.opencode/
+.claude/