Fix duplicate dependency constraint causing 500 errors

- Deduplicate dependencies by package name before inserting
- Some packages (like anyio) list the same dep (trio) multiple times with
  different version constraints for different extras
- The unique constraint on (artifact_id, project, package) rejected these
- Also removed debug logging from dependencies.py

backend/app/dependencies.py

@@ -10,11 +10,8 @@ Handles:
 - Conflict detection
 """
 
-import logging
 import re
 import yaml
-
-logger = logging.getLogger(__name__)
 from typing import List, Dict, Any, Optional, Set, Tuple
 from sqlalchemy.orm import Session
 from sqlalchemy import and_
@@ -435,8 +432,6 @@ def _resolve_dependency_to_artifact(
     if not package:
         return None
 
-    logger.info(f"_resolve_dependency_to_artifact: package_id={package.id}, version={version!r}, tag={tag!r}")
-
     if version:
         # Check if this is a version constraint (>=, <, etc.) or exact version
         if _is_version_constraint(version):
@@ -454,7 +449,6 @@ def _resolve_dependency_to_artifact(
                     Artifact.id == pkg_version.artifact_id
                 ).first()
                 if artifact:
-                    logger.info(f"_resolve_dependency_to_artifact: found by version {version}")
                     return (artifact.id, version, artifact.size)
 
         # Also check if there's a tag with this exact name
@@ -462,7 +456,6 @@ def _resolve_dependency_to_artifact(
             Tag.package_id == package.id,
             Tag.name == version,
         ).first()
-        logger.info(f"_resolve_dependency_to_artifact: tag lookup by version name, found={tag_record is not None}")
         if tag_record:
             artifact = db.query(Artifact).filter(
                 Artifact.id == tag_record.artifact_id
@@ -476,7 +469,6 @@ def _resolve_dependency_to_artifact(
             Tag.package_id == package.id,
             Tag.name == tag,
         ).first()
-        logger.info(f"_resolve_dependency_to_artifact: tag lookup by tag param, found={tag_record is not None}")
         if tag_record:
             artifact = db.query(Artifact).filter(
                 Artifact.id == tag_record.artifact_id
@@ -484,9 +476,6 @@ def _resolve_dependency_to_artifact(
             if artifact:
                 return (artifact.id, tag, artifact.size)
 
-    # Debug: list actual tags
-    sample_tags = db.query(Tag).filter(Tag.package_id == package.id).limit(3).all()
-    logger.info(f"_resolve_dependency_to_artifact: NOT FOUND. Sample tags: {[t.name for t in sample_tags]}")
     return None
 
 
@@ -670,12 +659,9 @@ def resolve_dependencies(
         CircularDependencyError: If circular dependencies are detected
         DependencyConflictError: If conflicting versions are required
     """
-    logger.info(f"resolve_dependencies: project={project_name}, package={package_name}, ref={ref!r}")
-
     # Resolve the initial artifact
     project = db.query(Project).filter(Project.name == project_name).first()
     if not project:
-        logger.warning(f"resolve_dependencies: project '{project_name}' not found")
         raise DependencyNotFoundError(project_name, package_name, ref)
 
     package = db.query(Package).filter(
@@ -683,11 +669,8 @@ def resolve_dependencies(
         Package.name == package_name,
     ).first()
     if not package:
-        logger.warning(f"resolve_dependencies: package '{package_name}' not found in project '{project_name}'")
         raise DependencyNotFoundError(project_name, package_name, ref)
 
-    logger.info(f"resolve_dependencies: found package id={package.id}")
-
     # Try to find artifact by tag or version
     resolved = _resolve_dependency_to_artifact(
         db, project_name, package_name, ref, ref

backend/app/pypi_proxy.py

@@ -737,8 +737,16 @@ async def pypi_download_file(
         # Extract and store dependencies
         dependencies = _extract_dependencies(content, filename)
         if dependencies:
-            logger.info(f"PyPI proxy: extracted {len(dependencies)} dependencies from {filename}")
+            # Deduplicate dependencies by package name (keep first occurrence)
+            seen_packages = set()
+            unique_deps = []
             for dep_name, dep_version in dependencies:
+                if dep_name not in seen_packages:
+                    seen_packages.add(dep_name)
+                    unique_deps.append((dep_name, dep_version))
+
+            logger.info(f"PyPI proxy: extracted {len(unique_deps)} dependencies from {filename} (deduped from {len(dependencies)})")
+            for dep_name, dep_version in unique_deps:
                 # Check if this dependency already exists for this artifact
                 existing_dep = db.query(ArtifactDependency).filter(
                     ArtifactDependency.artifact_id == sha256,