feat: add Profile Manager test page (NIP-07 + NIP-46 bunker)

New docs/test-bunker.html — edit kind 0 profiles via window.nostr
or NIP-46 remote signing through relay.nostrkeep.com. Adds nav
links from test.html and test-qr-codes.html.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: vveerrgg