Release 0.3.0: private-beta gate + anonymous read mode

Adds an email allowlist (toggleable per deployment) that restricts
OAuth sign-in to listed emails while keeping read paths public.
Anonymous visitors now see the full app shell in read-only mode
instead of the §14.1 landing wall. Empty allowlist = gate off, so
deployments that don't enable it behave exactly as 0.2.3.

Also fixes single-finger scroll on /philosophy and other .chrome-pane
views on iOS Safari (.app: 100vh → 100dvh).

Renames deploy/nginx/rfc.wiggleverse.org.conf →
ohm.wiggleverse.org.conf to match the deployed-domain rename
(rfc.wiggleverse.org deprovisioned 2026-05-27).

See CHANGELOG.md for full details + upgrade steps.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

backend/migrations/011_allowlist.sql

@@ -0,0 +1,22 @@
+-- Private-beta email allowlist.
+--
+-- The framework supports a deployment-gated sign-in mode: when this
+-- table contains rows, only emails listed here (case-insensitively)
+-- may sign in via OAuth. Users already provisioned in the `users`
+-- table are grandfathered in by gitea_id and never re-checked against
+-- this list — so the operator who allow-listed themselves, signed in
+-- once, then removed their own email from the list does not lose
+-- access.
+--
+-- An empty `allowed_emails` table is the "open" state: no allowlist
+-- gate runs, and any successful OAuth sign-in provisions a new user
+-- as before. This means a fresh framework install behaves exactly as
+-- prior versions until the operator adds the first row, at which
+-- point the gate turns on for everyone not yet in `users`.
+
+CREATE TABLE allowed_emails (
+    email            TEXT PRIMARY KEY COLLATE NOCASE,
+    added_by_user_id INTEGER REFERENCES users(id) ON DELETE SET NULL,
+    note             TEXT,
+    created_at       TEXT NOT NULL DEFAULT (datetime('now'))
+);