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/app/auth.py

@@ -77,6 +77,43 @@ async def fetch_user_profile(config: Config, access_token: str) -> dict[str, Any
         return resp.json()
 
 
+def allowlist_is_active() -> bool:
+    """The private-beta gate is on iff the `allowed_emails` table has any
+    rows. Empty list means "open" — any successful OAuth provisions a
+    user; first row added flips the deployment into private-beta mode.
+    See `migrations/011_allowlist.sql` for the reasoning.
+    """
+    row = db.conn().execute("SELECT 1 FROM allowed_emails LIMIT 1").fetchone()
+    return row is not None
+
+
+def is_allowed_sign_in(profile: dict[str, Any]) -> bool:
+    """Decide whether a freshly-completed OAuth profile may sign in.
+
+    Three accept paths:
+      1. The allowlist is empty (gate off).
+      2. The Gitea profile's email is in `allowed_emails` (case-insensitive).
+      3. A `users` row already exists for this `gitea_id` — grandfather
+         per `migrations/011_allowlist.sql`.
+    """
+    gitea_id = profile.get("id")
+    if gitea_id is not None:
+        existing = db.conn().execute(
+            "SELECT 1 FROM users WHERE gitea_id = ? LIMIT 1", (gitea_id,)
+        ).fetchone()
+        if existing is not None:
+            return True
+    if not allowlist_is_active():
+        return True
+    email = (profile.get("email") or "").strip()
+    if not email:
+        return False
+    row = db.conn().execute(
+        "SELECT 1 FROM allowed_emails WHERE email = ? LIMIT 1", (email,)
+    ).fetchone()
+    return row is not None
+
+
 def provision_user(config: Config, profile: dict[str, Any]) -> SessionUser:
     """Insert or update the users row for this Gitea profile.