generate_context_fingerprint() has no way to set timezone or locale

[rubenvereecken]

generate_context_fingerprint() and launch_options() don't coordinate on timezone and locale. Geoip resolves these in launch_options(), but the init script is already baked by generate_context_fingerprint() before geoip runs. There's no way to pass pre-resolved timezone/locale to the fingerprint generator.

This matters for profile-persistence workflows: resolve geoip once for a proxy IP, pin the timezone/locale, reuse across sessions without re-resolving. Currently there's no clean API for this — timezone only enters the fingerprint if the preset includes it (most don't), and locale has no path in at all.

Proposed fix

1. Add timezone and locale params to generate_context_fingerprint() — injected into config before init_script generation
2. In launch_options(), use setdefault for geoip timezone/locale keys so pre-set values aren't overwritten

This is somewhat opinionated — it fits workflows where one IP maps to one-or-more profiles, and a profile is never used with a different IP. Opt-in: callers who don't pass these params get current behaviour.