feat: simplify git mounts to use direct URLs instead of repo references

- Change git mount schema from repo_id to remote_url
- Remove database lookups for git mount resolution
- Clone directly from URL at instance startup
- Simplify frontend UI to text input for Git URL
- Fix route ordering in git_repositories.py to prevent 422 errors
- Update all tests to use remote_url field

Breaking change: Git mounts now use remote_url instead of repo_id

apps/api/src/services/config_profile_resolver.py

@@ -176,13 +176,13 @@ def _merge_git_mounts(
 ) -> list[dict[str, Any]]:
     """Merge git mounts from included profiles.
 
-    Later mounts override earlier ones with the same repo_id + target_path combo.
+    Later mounts override earlier ones with the same remote_url + target_path combo.
     """
     result = list(base)
-    # Build lookup by (repo_id, target_path)
-    seen = {(m["repo_id"], m["target_path"]): i for i, m in enumerate(result)}
+    # Build lookup by (remote_url, target_path)
+    seen = {(m["remote_url"], m["target_path"]): i for i, m in enumerate(result)}
     for mount in overlay:
-        key = (mount["repo_id"], mount["target_path"])
+        key = (mount["remote_url"], mount["target_path"])
         if key in seen:
             result[seen[key]] = dict(mount)
         else: