feat(uxcp): country auto-detect, persona smart defaults, ux polish

[MaryWylde]

• CountryBiasMap: pre-select the user's country on mount via IANA timezone (53-country lookup) with navigator.language fallback. No permission prompt, no network call. Selection only — biases are not auto-filled until the user clicks the action button.
• CountryBiasMap: drop the orphaned tagline field; restore the subTagline block in the header (types + en/ru/hy locales).
• BiasPanel: bump font sizes (BiasNumber 11→14, BiasName 14→16, BiasShort 12→14 with 8-line scroll cap, FooterMeta 12→14, Rationale 13→16, RegionTag/ConfidenceBadge 12→14); interpolate the country name into the "Use in Persona Builder" button label.
• CountryList: bump 14px elements to 16, sub-14 elements to 14.
• hy locale: replace "կողմնակալություն" with "հակում" everywhere (correct Armenian term for cognitive bias); all suffix forms remain grammatically valid via stem swap.
• UXCPLayout: auto-select the most relevant persona stage when bias relevancy data first becomes available; smooth-scroll to the persona section when biases are applied from the country panel.
• PersonaRelatedQuestions: default the priority filter to the dominant relevancy bucket for the active stage; user clicks override and persist for the rest of the session.
• ci(playwright): support HTTP Basic Auth for staging tests — read PLAYWRIGHT_HTTP_USERNAME/PASSWORD from env in playwright.config.ts and pass them through the scheduled workflow only when the target is not production.