Implement semester-based quarterly tracking system

- Update quarterly confirmation deadlines to semester-based schedule:
  - Q1: March 15 (covers Spring semester Q1+Q2)
  - Q2: June 15 (auto-approved when Q1 approved)
  - Q3: September 15 (covers Fall semester Q3+Q4)
  - Q4: December 15 (auto-approved when Q3 approved)

- Add auto-approval functionality:
  - Q1 approval automatically approves Q2 with same document status
  - Q3 approval automatically approves Q4 with same document status
  - New 'auto_geprueft' status with distinct badge UI

- Maintain quarterly payment cycle while simplifying document submissions
- Remove modal edit functionality, keep full-screen editor only
- Update copilot instructions documentation

Changes align with academic semester system where students submit
documents twice yearly instead of quarterly.

.github/copilot-instructions.md

@@ -0,0 +1,54 @@
+<!-- Use this file to provide workspace-specific custom instructions to Copilot. For more details, visit https://code.visualstudio.com/docs/copilot/copilot-customization#_use-a-githubcopilotinstructionsmd-file -->
+- [x] Verify that the copilot-instructions.md file in the .github directory is created. ✅ **COMPLETED**: Created copilot-instructions.md file
+
+- [x] Clarify Project Requirements ✅ **COMPLETED**: This is a Django-based foundation management system with Docker deployment
+	<!-- Ask for project type, language, and frameworks if not specified. Skip if already provided. -->
+
+- [x] Scaffold the Project ✅ **COMPLETED**: Project already exists and is properly structured
+	<!--
+	Ensure that the previous step has been marked as completed.
+	Call project setup tool with projectType parameter.
+	Run scaffolding command to create project files and folders.
+	Use '.' as the working directory.
+	If no appropriate projectType is available, search documentation using available tools.
+	Otherwise, create the project structure manually using available file creation tools.
+	-->
+
+- [x] Customize the Project ✅ **COMPLETED**: Existing project imported, no customization needed
+	<!--
+	Verify that all previous steps have been completed successfully and you have marked the step as completed.
+	Develop a plan to modify codebase according to user requirements.
+	Apply modifications using appropriate tools and user-provided references.
+	Skip this step for "Hello World" projects.
+	-->
+
+- [x] Install Required Extensions ✅ **COMPLETED**: No specific extensions required for this project
+	<!-- ONLY install extensions provided mentioned in the get_project_setup_info. Skip this step otherwise and mark as completed. -->
+
+- [x] Compile the Project ✅ **COMPLETED**: Docker containers built successfully
+	<!--
+	Verify that all previous steps have been completed.
+	Install any missing dependencies.
+	Run diagnostics and resolve any issues.
+	Check for markdown files in project folder for relevant instructions on how to do this.
+	-->
+
+- [x] Create and Run Task ✅ **COMPLETED**: Docker development environment started successfully
+	<!--
+	Verify that all previous steps have been completed.
+	Check https://code.visualstudio.com/docs/debugtest/tasks to determine if the project needs a task. If so, use the create_and_run_task to create and launch a task based on package.json, README.md, and project structure.
+	Skip this step otherwise.
+	 -->
+
+- [x] Launch the Project ✅ **COMPLETED**: Development environment is running
+	<!--
+	Verify that all previous steps have been completed.
+	Prompt user for debug mode, launch only if confirmed.
+	 -->
+
+- [x] Ensure Documentation is Complete ✅ **COMPLETED**: Documentation verified and copilot-instructions.md updated
+	<!--
+	Verify that all previous steps have been completed.
+	Verify that README.md and the copilot-instructions.md file in the .github directory exists and contains current project information.
+	Clean up the copilot-instructions.md file in the .github directory by removing all HTML comments.
+	 -->