Prepare Matrix for migration and improve service health checks

- Updated .gitignore to selectively track Matrix config files
  - Allow: homeserver.yaml, *.log.config
  - Exclude: *.db*, media_store/, signing keys
- Added Matrix configuration files to repository
- Fixed BookStack environment variables (APP_KEY, DB_* pattern)
- Improved health checks for BookStack, JupyterHub, and Synapse
- All services now have proper health monitoring

matrix/data/localhost.log.config

@@ -0,0 +1,39 @@
+version: 1
+
+formatters:
+  precise:
+    
+    format: '%(asctime)s - %(name)s - %(lineno)d - %(levelname)s - %(request)s - %(message)s'
+    
+
+handlers:
+
+
+  console:
+    class: logging.StreamHandler
+    formatter: precise
+
+loggers:
+    # This is just here so we can leave `loggers` in the config regardless of whether
+    # we configure other loggers below (avoid empty yaml dict error).
+    _placeholder:
+        level: "INFO"
+
+    
+    
+    synapse.storage.SQL:
+        # beware: increasing this to DEBUG will make synapse log sensitive
+        # information such as access tokens.
+        level: INFO
+    
+
+    
+
+root:
+    level: INFO
+
+
+    handlers: [console]
+
+
+disable_existing_loggers: false