fix: Comprehensive validation and bug fixes

Infrastructure:
- Add Redis and Celery workers to all docker-compose files
- Fix celery migration race condition in entrypoint.sh
- Add healthchecks and resource limits to dev compose
- Update .env.template with Redis/Celery variables

Backend Models & Schemas:
- Rename Sprint.completed_points to velocity (per requirements)
- Add AgentInstance.name as required field
- Rename Issue external tracker fields for consistency
- Add IssueSource and TrackerType enums
- Add Project.default_tracker_type field

Backend Fixes:
- Add Celery retry configuration with exponential backoff
- Remove unused sequence counter from EventBus
- Add mypy overrides for test dependencies
- Fix test file using wrong schema (UserUpdate -> dict)

Frontend Fixes:
- Fix memory leak in useProjectEvents (proper cleanup)
- Fix race condition with stale closure in reconnection
- Sync TokenWithUser type with regenerated API client
- Fix expires_in null handling in useAuth
- Clean up unused imports in prototype pages
- Add ESLint relaxed rules for prototype files

CI/CD:
- Add E2E testing stage with Testcontainers
- Add security scanning with Trivy and pip-audit
- Add dependency caching for faster builds

Tests:
- Update all tests to use renamed fields (velocity, name, etc.)
- Fix 14 schema test failures
- All 1500 tests pass with 91% coverage

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

backend/tests/tasks/test_git_tasks.py

@@ -12,9 +12,8 @@ Note: These tests mock actual execution since they would require
 Git operations and external APIs in production.
 """
 
-import pytest
-from unittest.mock import patch
 import uuid
+from unittest.mock import patch
 
 
 class TestCloneRepositoryTask:
@@ -22,8 +21,8 @@ class TestCloneRepositoryTask:
 
     def test_clone_repository_task_exists(self):
         """Test that clone_repository task is registered."""
-        from app.celery_app import celery_app
         import app.tasks.git  # noqa: F401
+        from app.celery_app import celery_app
 
         assert "app.tasks.git.clone_repository" in celery_app.tasks
 
@@ -72,8 +71,8 @@ class TestCommitChangesTask:
 
     def test_commit_changes_task_exists(self):
         """Test that commit_changes task is registered."""
-        from app.celery_app import celery_app
         import app.tasks.git  # noqa: F401
+        from app.celery_app import celery_app
 
         assert "app.tasks.git.commit_changes" in celery_app.tasks
 
@@ -114,8 +113,8 @@ class TestCreateBranchTask:
 
     def test_create_branch_task_exists(self):
         """Test that create_branch task is registered."""
-        from app.celery_app import celery_app
         import app.tasks.git  # noqa: F401
+        from app.celery_app import celery_app
 
         assert "app.tasks.git.create_branch" in celery_app.tasks
 
@@ -156,8 +155,8 @@ class TestCreatePullRequestTask:
 
     def test_create_pull_request_task_exists(self):
         """Test that create_pull_request task is registered."""
-        from app.celery_app import celery_app
         import app.tasks.git  # noqa: F401
+        from app.celery_app import celery_app
 
         assert "app.tasks.git.create_pull_request" in celery_app.tasks
 
@@ -201,8 +200,8 @@ class TestPushChangesTask:
 
     def test_push_changes_task_exists(self):
         """Test that push_changes task is registered."""
-        from app.celery_app import celery_app
         import app.tasks.git  # noqa: F401
+        from app.celery_app import celery_app
 
         assert "app.tasks.git.push_changes" in celery_app.tasks
 
@@ -254,7 +253,6 @@ class TestGitTaskRouting:
 
     def test_all_git_tasks_match_routing_pattern(self):
         """Test that all git task names match the routing pattern."""
-        from app.tasks import git
 
         task_names = [
             "app.tasks.git.clone_repository",