[tunjayoff]

Adds --source off to scripts/soak_live.py: no push source at all.

• The live service is built with requested_source="poll" (the service's push=False path, as ssc watch --source poll), so the arbiter's leader is poll for the whole run and the recorder's fallback rule (joined every 60 s, others backlog, skips counted, --rate-schedule phases) drives the REST reads at the configured rate.
• No credential reader, no direct connection, no page opener (the main bridge for REST reads stays).
• leader.jsonl start row: leader: poll, reason: push_off; no switches follow. summary.json, requests.jsonl and fallback.jsonl keep their shape (fallback_time_share 1.0, notes[0] explains source off).
• --kill-every / --kill-at (and, as before, --compare-credential-sports) are refused with --source off; Soak.kill returns False.
• Soak takes optional wall/mono clocks and begin() (the start records) is split from start() (threads), for the fake-clock test.

Tests (offline; no SofaScore, no browser):

• push off: leader poll from the start with reason push_off, no switch, no session or credential read (browser reader/opener patched to fail), minute reads joined 1 + listed 1, requests rows sum to the requests used.
• fake-clock run, no threads: rate schedule 1 min at 1/s then 5/s, 200 live matches, list share 0.5: fallback cap 30 → 150, requests per minute 31 → 151 (peak 1 s: 1 → 5), rate phases in summary 31 / 302.

tests/test_soak_live.py + tests/test_research_privacy.py: 49 passed; ruff check clean. No shared code touched.