✨ Add applications and project members functionality with schema updates

[andiazdi]

Closes #64
Closes #65
Closes #66

[Copilot]

Pull Request Overview

This PR implements application and project member functionality by extending the database schema, models, service logic, routes, and schemas to support apply/approve workflows and adds new project attributes.

• Adds Application and ProjectMember models, migrations, and data-access methods for project applications and members
• Extends ProjectService, routes, and Pydantic schemas to handle apply, list, and approve operations
• Updates database dependency to centralize commits and refines user ID typing in auth services

Reviewed Changes

Copilot reviewed 23 out of 23 changed files in this pull request and generated 5 comments.

Show a summary per file

File	Description
backend/app/models/applications.py	New Application model for user-project applications
backend/app/models/project_member.py	New ProjectMember model for approved project members
backend/app/models/projects.py	Added ceo_id, is_opensource, is_dead, and __repr__
backend/app/models/users.py	Made role column nullable
backend/app/routes/api/project/schemas.py	Extended project, application, and member schemas
backend/app/routes/api/project/data_access.py	Added data-access logic and custom exception for applications
backend/app/routes/api/project/service.py	Service methods for apply, list, and approve workflows
backend/app/routes/api/project/router.py	New routes for project application endpoints
backend/app/dependencies/database.py	Moved commit into DB dependency
backend/app/services/auth.py	Updated get_user_by_username return type
backend/app/schemas/user.py	Added optional id field to UserInDB

Comments suppressed due to low confidence (2)

backend/app/routes/api/project/schemas.py:38

• [nitpick] ProjectMemberSchema omits created_at even though the model records it. Add created_at: datetime (or date) to the schema for consistency.

class ProjectMemberSchema(BaseModel):

backend/app/models/users.py:22

• [nitpick] The role column was made nullable, potentially allowing users without a role. For data integrity, consider keeping it non-nullable or adding a default.

        nullable=True,

[Copilot]

The approve_application call in service can raise ProjectNotFoundError and is not caught, resulting in a 500. Catch this exception and convert to an HTTPException with a 404 status.

[Copilot]

Tests reference a status field on ProjectSchema (e.g., status="active"), but ProjectSchema does not define status. Add status: str to the schema.

[Copilot]

[nitpick] The exception ProjectNotFoundError is used for missing application records. Consider renaming it to ApplicationNotFoundError for clarity.

Suggested change

	class ProjectNotFoundError(Exception):
	class ApplicationNotFoundError(Exception):

[Copilot]

ApplicationSchema.created_at is typed as datetime but the model uses SQL Date. Either change the column to DateTime or update the schema to date.

Suggested change

	created_at = Column(Date, default=func.current_date())
	created_at = Column(DateTime, default=func.current_timestamp())

[andiazdi]

fixing

[Copilot]

[nitpick] Committing in the DB dependency will commit after all operations, including GET requests. Consider committing only in write operations or in service methods.

Suggested change

await session.commit()