* fix(setup): tolerate reserved memory in the RAM preflight, add OMNIVOICE_RAM_PREFLIGHT=0 escape hatch (#1618)
An "8 GB" machine reports ~7.8 GB usable (firmware/iGPU/kernel
reservations), so comparing OS-reported RAM against the marketing-size
8 GB threshold hard-blocked exactly the boundary hardware the minimum is
meant to admit — with no way past the wizard. Both thresholds are now
compared with a 7% reserved-memory allowance, and
OMNIVOICE_RAM_PREFLIGHT=0 downgrades a genuine fail to a warning for
users who accept the OOM risk (same opt-out shape as
OMNIVOICE_ASR_VRAM_PREFLIGHT).
Regression tests: backend/tests/test_ram_preflight_1618.py.
Docs: troubleshooting §1c.
* review: hermetic preflight stubs in tests; correct the escape-hatch doc
Greptile P1: the Settings panel can't set OMNIVOICE_RAM_PREFLIGHT (and the
blocker appears before setup completes anyway) — the doc now points at
PowerShell / shell env only.
CodeRabbit: stub _network_check and media_tools.summary so each RAM
assertion stays fast and offline (26s -> 6s locally).
Palash Debnath
2d37627ab2