refactor(repo): consolidate openflare-server to root and move subprojects to internal/apps

- Merge all files inside openflare-server to the repository root directory.
- Relocate agent, relay, and flared subprojects from internal/ to internal/apps/.
- Combine docker-compose files and update build context paths to root.
- Update GitHub workflows and Dockerfiles to refer to new directories and package names.
- Rewrite Go package imports across all files.
- Resolve database renew test race condition and clean up docs.

.editorconfig

@@ -0,0 +1,19 @@
+root = true
+
+[*]
+indent_style = space
+indent_size = 4
+charset = utf-8
+end_of_line = lf
+trim_trailing_whitespace = true
+insert_final_newline = true
+
+[*.{json,yml,yaml}]
+indent_size = 2
+
+[*.md]
+insert_final_newline = false
+trim_trailing_whitespace = false
+
+[*.{js,ts,css,html,jsx,tsx,vue}]
+indent_size = 2