refactor(profile): centralize profile URL building with NIP-05-aware routing

[DSanich]

refactor(profile): centralize profile URL building with NIP-05-aware routing

Profile links are currently built ad-hoc in multiple places, and at least one path still uses an explicit “for now” fallback (npub-only URL construction in VideoCard).
This creates route inconsistency, makes future profile routing changes risky, and increases the chance of user-facing navigation drift.

Problem

• Profile URL construction is not centralized.
• Some call sites still rely on temporary npub-only link generation.
• Route behavior can diverge between components over time.

Scope

• Introduce a shared profile-link utility (or hook helper) in a single module.
• Make the helper NIP-05-aware (when data is available) with a deterministic fallback to npub.
• Replace direct profile URL string-building in affected components (starting with VideoCard and other high-traffic profile-entry points).
• Keep existing navigation behavior backward-compatible (no breaking route changes in this issue).

Out of scope

• Changing public profile route format across the whole app.
• New profile discovery UX.
• Backend identity resolution changes.

Definition of done

• Profile links in targeted components are built through one shared helper.
• No remaining “for now” profile-link comment in VideoCard.
• Navigation remains stable for users with and without NIP-05 metadata.
• No regressions in profile-link related tests (or add targeted tests if coverage is missing).

[DSanich]

@jalcine I prepared PR for this refactor issue. Could you look, please.

cc @NotThatKindOfDrLiz @rabble