feat: complete Epic 0 — foundation migration & infrastructure setup

Stories 0.2-0.5: rename folders→declarations (backend+frontend), configure
Redis for cache/queue/sessions, add foundation database migrations
(permissions, archived_at), replace DeclarationStatus enum with architecture
lifecycle values, create DeclarationObserver for status transition validation
and auto-archive, fix controller status transitions to respect observer rules.

93 tests pass (240 assertions).

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

compose.yaml

@@ -22,7 +22,22 @@ services:
         networks:
             - sail
         depends_on:
-            - mailpit
+            mailpit:
+                condition: service_started
+            redis:
+                condition: service_healthy
+    redis:
+        image: 'redis:alpine'
+        ports:
+            - '${FORWARD_REDIS_PORT:-6379}:6379'
+        volumes:
+            - 'sail-redis:/data'
+        networks:
+            - sail
+        healthcheck:
+            test: ["CMD", "redis-cli", "ping"]
+            retries: 3
+            timeout: 5s
     mailpit:
         image: 'axllent/mailpit:latest'
         ports:
@@ -33,3 +48,6 @@ services:
 networks:
     sail:
         driver: bridge
+volumes:
+    sail-redis:
+        driver: local