v2.2.0

Named profiles (#1) + landing polish

Profiles (closes #1):
- State model: profiles [{id,name,urlRegex,headers,sources}] + activeProfileId;
  appearance/master stay global. Only the active profile is injected.
- loadState migrates the pre-profiles flat shape into a "Default" profile — no
  data loss for existing installs. activeProfile(state) resolves the current one.
- Popup: profile bar (switch dropdown + new/duplicate/rename/delete). All header/
  source/scope access routed through prof().
- Importing a shared config now lands as a NEW profile instead of merging.

Landing:
- Drop the redundant nav brand (icon+title repeated right above the hero).
- Add "Named profiles" to the feature list; regenerate all three screenshots
  with the profile bar visible.

Bump 2.1.0 -> 2.2.0.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>