Add guild-styled HTML templates for OIDC logout confirmation, post-logout
success, and error pages. Update wiki login heading to brand convention
(candlelight + warm-text). Restyle magic link email from blue to guild
colour tokens.
The /oidc/[...] server catch-all was intercepting /oidc/login before
the Nuxt page router could render it. Moving the page outside /oidc/
avoids the conflict entirely.
