Feat/motivation features

[udaykiran-404]

Summary of Changes

Implemented 6 locked behavioral and gamification features to extend the Spurti Motivation Engine with agency, self-regulation, and engagement mechanisms.

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Core Features Added

1. Streaks Engine 🔥

   • Tracks consecutive attendance qualifications (present $\ge 75%$ and answering $\ge 75%$ of polls when launched).
   • Streak counters are rendered live in the student Level Tiles dashboard.
   • Automatically awards an SP Shield for every 10 consecutive qualified sessions.

2. SP Shield 🛡️

   • Added a Shield Shop card and transaction type. Students can purchase shields for 30 SP (capped at 3 shields max).
   • Restricted shield purchases to only 1 shield per week (7 days).
   • Automatically consumes a shield to protect streaks during missed/failed sessions and awards baseline attendance points (+5 SP).

3. Weekly Goal & Reflections 🎯✍️

   • Created a new Reflection schema.
   • Added a new Goals & Reflections tab in the client UI.
   • Allows setting weekly SP targets with a dynamic, beautiful progress bar displaying SP Earned, SP Remaining, and completion percentage.
   • Students can submit a weekly self-reflection text to claim a +5 SP reward.

4. Recovery Missions 🌟

   • Automatically triggers a comeback mission for students whose streaks reset.
   • Requires 3 consecutive qualified sessions to recover +15 SP. Progress is displayed via a progress card in the student pulse grid.

5. Badge Gallery 🏆

   • Added a comprehensive Badge Gallery representing 8 system achievements.
   • Displays description and visual indicator showing unlocked badges (vibrant color) vs locked badges (translucent with a 🔒 lock icon).

6. Educator Nudges 📢

   • Enabled admins to send custom nudges directly to student dashboards.
   • Students receive unread notifications in a prominent header alert banner with a "Dismiss" action.

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Technical Architecture Updates

• Models: Updated Student.js and SPTransaction.js, and created Reflection.js.
• Scoring Pipeline: Patched sp-rubric-build-mirror.cjs to query manual/shop transactions and run streaks/shield/mission logic sequentially from scratch (maintains idempotent replay capability).
• Server APIs: Added endpoints for purchase, goals, submissions, admin nudging, and read triggers in server.js.
• Security/Local Auth: Added X-Student-Email headers to facilitate action requests (goals/shop) under local student search confirmation modes.
• Frontend & Styling: Designed and integrated tab navigation, components, progress bars, grid layouts, and styles in main.jsx and styles.css.