Deprecates branch_short_code, auto-refreshes default CSRF token and updates contributor section on README

[ndigvijay]

📌 Description

Please provide a concise summary of the changes:

• What is the purpose of this PR?
• What problem does it solve, or what feature does it add?
• Any relevant motivation, background, or context?

ℹ️ Fixes / Related Issues
Fixes: #123
Related: #456

🧱 Type of Change

Please indicate the type of changes introduced in your PR. Anything left unchecked will be assumed to be non-relevant

• 🐛 Bug fix – Non-breaking fix for a functional/logic error
• ✨ New feature – Adds functionality without breaking existing APIs
• ⚠️ Breaking change – Introduces backward-incompatible changes (API, schema, etc.)
• 📝 Documentation update – README, docstrings, OpenAPI tags, etc.
• 🧪 Test suite change – Adds/updates unit, functional, or integration tests
• ⚙️ CI/CD pipeline update – Modifies GitHub Actions, pre-commit, or Docker build
• 🧹 Code quality / Refactor – Improves structure, readability, or style (no functional changes)
• 🐢 Performance improvement – Speeds up auth, scraping, or reduces I/O
• 🕵️ Debug/logging enhancement – Adds or improves logging/debug support
• 🔧 Developer tooling – Scripts, benchmarks, local testing improvements
• 🔒 Security fix – Addresses auth/session/data validation vulnerabilities
• 🧰 Dependency update – Updates libraries in requirements.txt, pyproject.toml

🧪 How Has This Been Tested?

Please indicate how you tested your changes. Completing all the relevant items on this list is mandatory

• Unit Tests (tests/unit/)
• Functional Tests (tests/functional/)
• Integration Tests (tests/integration/)
• Manual Testing

⚙️ Test Configuration:

• OS: (e.g., Linux)
• Python: (e.g., 3.12 via uv)
• Docker build tested

✅ Checklist

Please indicate the work items you have carried out. Completing all the relevant items on this list is mandatory. Anything left unchecked will be assumed to be non-relevant

• My code follows the CONTRIBUTING.md guidelines
• I've performed a self-review of my changes
• I've added/updated necessary comments and docstrings
• I've updated relevant docs (README or endpoint docs)
• No new warnings introduced
• I've added tests to cover my changes
• All tests pass locally (scripts/run_tests.py)
• I've run linting and formatting (pre-commit run --all-files)
• Docker image builds and runs correctly
• Changes are backwards compatible (if applicable)
• Feature flags or .env vars updated (if applicable)
• I've tested across multiple environments (if applicable)
• Benchmarks still meet expected performance (scripts/benchmark_auth.py)

🛠️ Affected API Behaviour

Please indicate the areas affected by changes introduced in your PR

• app/app.py – Modified /authenticate route logic
• app/pesu.py – Updated scraping or authentication handling
• app/util.py – General helper functions

🧩 Models

• app/models/request.py – Input validation or request schema changes
• app/models/response.py – Authentication response formatting
• app/models/profile.py – Profile extraction logic

🐳 DevOps & Config

• Dockerfile – Changes to base image or build process
• .github/workflows/*.yaml – CI/CD pipeline or deployment updates
• pyproject.toml / requirements.txt – Dependency version changes
• .pre-commit-config.yaml – Linting or formatting hook changes

📊 Benchmarks & Analysis

• scripts/benchmark_auth.py – Performance or latency measurement changes
• scripts/analyze_benchmark.py – Benchmark result analysis changes
• scripts/run_tests.py – Custom test runner logic or behavior updates

📸 Screenshots / API Demos (if applicable)

Add any visual evidence that supports your changes. MANDATORY for breaking changes.

Examples:

• Terminal output from a successful curl request (redact sensitive data)
• Screenshots of Postman/Bruno results
• GIF of the endpoint working in a browser
• JSON payloads (redact sensitive data)

🧠 Additional Notes (if applicable)

Use this space to add any final context or implementation caveats.

Examples:

• Edge cases or limitations to be aware of
• Follow-up work or tech debt to track
• Known compatibility issues (e.g., with certain Python versions)
• Any new issues this PR introduces or makes visible