Eliminate N+1 queries and optimize database operations

[Copilot]

The API exhibited multiple N+1 query patterns causing excessive database round trips, particularly in project listing and quota endpoints. Additional inefficiencies included redundant session creation and multi-pass password validation.

Changes

N+1 Query Elimination

• list_openstack_project_for_user: Batch fetch projects, memberships, and users instead of querying per-project and per-member (O(n²) → O(1) queries)
• remove_user_from_project: Batch fetch member users (O(n) → O(1) queries)
• show_project_adjustements: Batch fetch users for quota shares (O(n) → O(1) queries)

Session Reuse

• Added optional session: Optional[Session] parameter to quota calculation functions (calculate_user_quota_by_type, calculate_user_quota, calculate_project_quota, get_user_left_quota_by_type)
• Updated callers to pass existing sessions, eliminating redundant session creation

Password Validation

• Single-pass validation with early exit replaces 5 separate iterations (O(5n) → O(n))

Bug Fix

• ProxyManager: Fixed missing service.target in Traefik loadBalancer URL configuration

Example: Before/After N+1 Fix

# Before: O(n²) queries
for project in projects_owner:
    db_members = session.exec(select(ProjectUserMembership).where(...)).all()
    members=[
        session.exec(select(User).where(User.id == member.user_id)).first().username
        for member in db_members
    ]

# After: O(1) queries  
all_project_ids = [...]
projects = {p.id: p for p in session.exec(select(Project).where(Project.id.in_(all_project_ids))).all()}
memberships = session.exec(select(ProjectUserMembership).where(ProjectUserMembership.project_id.in_(all_project_ids))).all()
users = {u.id: u.username for u in session.exec(select(User).where(User.id.in_(user_ids))).all()}

Original prompt

Identify and suggest improvements to slow or inefficient code

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[sonarqubecloud]

Please retry analysis of this Pull-Request directly on SonarQube Cloud

[sonarqubecloud]

Please retry analysis of this Pull-Request directly on SonarQube Cloud

[sonarqubecloud]

Quality Gate passed

Issues
5 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud