Build a school management system (ERP) with parent app

You are a senior developer who builds software for schools. Build a school management system with me, phase by phase, with web portals for staff and a mobile-friendly portal for parents and students.

## The school
- School name and board: [NAME], [e.g. CBSE, ICSE, state board, IB]
- Number of students and classes: [NUMBERS]
- Branches: [NUMBER]
- Users: [admin, principal, teachers, accountant, parents, students]
- Fee payment gateway: [GATEWAY]
- Tech stack I prefer: [STACK or "you choose"]

## Features
1. Admissions: online enquiry and application form, document upload, test or interview scheduling, admission approval, student ID generation.
2. Students: profiles, class and section, siblings, documents, transfer certificates, promotion to the next year.
3. Attendance: daily or period-wise from a phone, automatic SMS or app message to parents of absent students, monthly reports.
4. Timetable builder with teacher clash detection, substitution management.
5. Exams: exam schedules, marks entry by subject teachers, grading rules, report cards as PDF in the board's format, rank lists.
6. Homework and class notes posted by teachers, seen by parents.
7. Fees: fee structures by class, concessions, instalments, online payment, receipts, due reminders, defaulter lists, daily collection report.
8. Communication: circulars, events calendar, parent-teacher meeting booking, two-way messages with teachers.
9. Staff: profiles, attendance, leave, payroll export.
10. Optional modules: library, transport (routes, bus fees), hostel, inventory.
11. Dashboards for principal and admin; academic year rollover.

## School rules
- Child data is sensitive: role-based access, parents see only their own children, audit log of record views.
- Works well on low-end phones and slow connections.
- Multi-language support for parent communication.

## Quality rules (apply to every phase)
- Security: prepared statements or an ORM for every query, output escaping, CSRF tokens on every form, passwords hashed with bcrypt or Argon2, rate-limited login, role checks on the server for every admin route, file uploads checked by type and size and stored outside the web root or with random names, secrets only in an .env file.
- Validation: validate every input on the server (and also in the browser for speed). Show clear error messages next to the field that is wrong, and keep what the user already typed.
- Performance: pagination on every list, database indexes on every column used for search, filter or join, lazy-loaded and resized images (WebP), caching for pages that rarely change, no N+1 queries.
- Responsive and accessible: mobile first, works from 360px to wide desktop, proper labels on every form field, keyboard navigation, visible focus, colour contrast of at least 4.5:1, alt text on images.
- SEO: clean URLs, a unique title and meta description per page, canonical tags, Open Graph tags, schema.org JSON-LD where it applies, an XML sitemap and robots.txt.
- Code: small functions with clear names, one responsibility per file, comments only where the reason is not obvious, consistent formatting, no dead code.
- Errors: friendly error pages (404, 500), server errors written to a log, never shown to visitors.
- Deliver with: a README (install steps, .env example, how to create the first admin), database migrations and seed data with realistic sample content, and a deployment checklist.

## How to work with me
Do not write code yet. First reply with:
1. A short summary of what you understood, and anything in the brief that is unclear or contradictory (ask me, do not guess).
2. The final tech stack, with a one-line reason for each choice.
3. The folder and file structure.
4. The full database schema: every table, column, type, index and relation.
5. Every page or screen, and every API endpoint (method, path, who can call it, what it returns).
6. The build plan as numbered phases, each one small enough to finish and test on its own.

Wait for me to reply "go". Then build one phase at a time:
- For every file, give the full path and the complete code. Never write "...", "rest of the code stays the same" or TODO.
- After each phase, tell me how to run it, what to click to test it, and what is still missing. Then wait for me to reply "next".
- If you change a file you already gave me, give the whole updated file again.