feat(fase-1): auth, collective management, and DB migrations

- SQL migrations: users, collectives, collective_members, collective_invitations,
  full RLS policies, is_active_member/is_member/is_admin helpers,
  accept_invitation SECURITY DEFINER function, admin auto-promote trigger,
  avatars storage bucket
- Auth refactor: replace keycloak-js with Supabase OAuth (GoTrue OIDC proxy,
  Option B). signInWithOAuth({ provider: 'keycloak' }) + PKCE flow
- GoTrue config: GOTRUE_EXTERNAL_KEYCLOAK_URL + GOTRUE_EXTERNAL_KEYCLOAK_REDIRECT_URI
  added to docker-compose.dev.yml; Keycloak realm updated with GoTrue callback URI
- New routes: /auth/callback, /invitation/[token], /(app)/collective/manage
- Functional onboarding: create collective or join via invite link
- Full settings page: display name (debounced), avatar (initials/emoji/upload),
  language switcher, Keycloak account console link
- Components: Avatar.svelte (initials/emoji/upload with fallback),
  ImageCropper.svelte (cropperjs, 1:1 crop, lazy-loaded)
- i18n: added all Fase 1 message keys (en + es); renamed 'delete' → 'action_delete'
  (JS reserved word); fixed plugin-m-function-matcher major-version URL format
- Database types: manually seeded packages/types/src/database.ts from migrations
- .env.development: committed public dev defaults for SvelteKit type checking
- CLAUDE.md: documented /etc/hosts requirement for keycloak hostname

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

supabase/config.toml

@@ -65,10 +65,14 @@ enable_confirmations = false
 enable_signup = false
 enable_confirmations = false
 
-# Keycloak as OIDC provider
-# The JWT_SECRET must be set to the Keycloak RS256 public key
+# Keycloak as external OIDC provider via GoTrue (Option B).
+# GoTrue acts as OIDC proxy: app → GoTrue → Keycloak → GoTrue issues Supabase JWT.
+# Configured via environment variables in docker-compose.dev.yml:
+#   GOTRUE_EXTERNAL_KEYCLOAK_ENABLED, GOTRUE_EXTERNAL_KEYCLOAK_URL, etc.
+# The [auth.third_party.keycloak] section is for Supabase CLI managed stacks;
+# we use docker-compose directly so this section is intentionally left empty.
 [auth.third_party.keycloak]
-enabled = false  # We bypass GoTrue — Keycloak JWT validated directly by PostgREST
+enabled = false
 
 [edge_runtime]
 enabled = true