fix: add request timeouts to prevent indefinite hangs (#239)

[bjornars]

Summary

• Set a default (10s connect, 2min read) timeout on every requests.Session via functools.partial on session.request — one line in NovemAPI.__init__ covers all subclasses with no per-call-site changes
• job.run() overrides to (30s connect, 30min read) since job execution can legitimately take up to 30 minutes
• Applied the same fix to NovemGQL which manages its own session independently and was not covered by the NovemAPI change

How it works

self._session.request = functools.partial(self._session.request, timeout=(10, 120))

functools.partial keyword arguments are overridable at call time, so job.run() can pass timeout=(30, 1800) and it takes precedence over the default.

Test plan

• test_session_default_timeout — mocks session.send and verifies the default (10, 120) timeout flows through the full chain (functools.partial → session.request → session.send) for an ordinary API call
• test_job_run_no_files_uses_job_timeout — same approach, verifies (30, 1800) for the empty-JSON branch of run()
• test_job_run_with_files_uses_job_timeout — same for the multipart-upload branch of run()

Closes #239