Monorepo: consolidate 7 repos into one

Combines shared, blog, market, cart, events, federation, and account
into a single repository. Eliminates submodule sync, sibling model
copying at build time, and per-app CI orchestration.

Changes:
- Remove per-app .git, .gitmodules, .gitea, submodule shared/ dirs
- Remove stale sibling model copies from each app
- Update all 6 Dockerfiles for monorepo build context (root = .)
- Add build directives to docker-compose.yml
- Add single .gitea/workflows/ci.yml with change detection
- Add .dockerignore for monorepo build context
- Create __init__.py for federation and account (cross-app imports)

market/bp/browse/services/state.py

@@ -0,0 +1,21 @@
+from typing import Dict, Tuple, List
+import time
+
+_nav_cache: dict = {}
+_nav_cache_ts: float = 0.0
+_nav_ttl_seconds = 60 * 60 * 6
+
+_detail_cache: Dict[str, Dict] = {}
+_detail_cache_ts: Dict[str, float] = {}
+_detail_ttl_seconds = 60 * 60 * 6
+
+KNOWN_PRODUCT_SLUGS: set[str] = set()
+
+_listing_variant_cache: Dict[str, Tuple[str, float]] = {}
+_listing_variant_ttl = 60 * 60 * 6
+
+_listing_page_cache: Dict[str, Tuple[Tuple[List[Dict], int], float]] = {}
+_listing_page_ttl = 60 * 30
+
+def now() -> float:
+    return time.time()