In-app notification inbox, consolidate /profile into /me, theme realign

In-app notification center (Phase 5, migration 051):
- notifications.read_at + partial unread index. /me Notifications is now
  an inbox: unread styling, click to expand the message + mark read,
  "mark all as read", unread count. markNotificationsRead is a service-
  client write scoped to the caller's own member_id. Always-on channel:
  email-muted ('skipped') notifications still appear in-app.

Consolidate /profile into /me:
- Delete app/(app)/profile/*; /me is the single member page. Port the
  conflict-of-interest privileged-role nudge + last-disclosed date into
  /me's profile editor. Remove the "My profile" sidebar + command-palette
  entries; rename the /me nav label to "My membership". Repoint the
  recruitment empty-state link to /me.

Theme realign:
- Revert the rounded-lg cards introduced in the prior /me visual pass to
  rounded (the app norm, matching the former /profile). Route /me section
  headers through the SectionTitle primitive.

Regression guard:
- integration/auth-embed.test.ts runs the auth layout's
  space_members.select('*, spaces(*)') embed through PostgREST and fails
  on PGRST201, so a future junction table cannot silently break auth again.

DB_SCHEMA_MAP.md

@@ -415,6 +415,8 @@ Default channels created by trigger on space INSERT: `general`, `announcements`,
 | 047 | `members_with_permission(sid, perm)` SECURITY DEFINER, set-returning inverse of `user_has_permission` (same current/late gate, same admin shortcut + `space_role_permissions`/`user_effective_roles` fallback). Lets Phase 4 fan-outs (e.g. `form_submission_admin`) resolve permission holders in one query. No new table/column/policy |
 | 048 | `notification_preferences` (Phase 5): per-member opt-out of muteable categories (`bookings, classes, forms, admin_alerts`); `billing` never muteable/stored. Cols `space_id, member_id, category, enabled`; PK `(space_id, member_id, category)`. Opt-out: no row = enabled. RLS on, NO client policy (default-deny); dispatcher reads via service client and marks muted rows `skipped`; `/me` view + toggle via validated service-client actions. `touch_updated_at` trigger |
 | 049 | `dues_payment_methods`: admin-configured external dues links. Cols `id, space_id, platform (payment_platform), url, instructions, is_active, sort_order`; `UNIQUE (space_id, platform)`. One pay-here URL per platform (PayPal/Zeffy/Venmo); members click out, treasurer reconciles manually (platform pre-typed). RLS: SELECT any space member, write admin/board. `url` validated https-only at the action boundary. `touch_updated_at` trigger |
+| 051 | `notifications.read_at timestamptz` + partial idx `idx_notifications_unread (space_id, member_id) WHERE read_at IS NULL`. In-app inbox read state on `/me`; unread = `read_at IS NULL`. Mark-read = service-client action scoped to caller's member_id (no RLS change). Email-muted (`skipped`) rows still show in-app |
+| 052 | HOTFIX: drop `notification_preferences_space_id_fkey`. FKs to BOTH space_members and spaces made the table a PostgREST junction -> `space_members.select('*, spaces(*)')` ambiguous (PGRST201) -> all logged-in users bounced to /signup. One FK left (member_id); space reachable + cascades via space_members. NEVER add a spaces FK to a space_members-referencing table. Guarded by integration/auth-embed.test.ts |
 | 050 | CHECK `dues_payment_methods_url_https` (`url ~* '^https://'`): the url renders as a member-clickable href and RLS lets admins write directly past the app Zod check, so the DB enforces https (no stored `javascript:`/`http:` XSS). Member-read action also re-filters with `isSafeDuesUrl`. Idempotent DO-block |
 
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