feat: add reminders page, BMad skills upgrade, MCP server refactor

- Add reminders page with navigation support
- Upgrade BMad builder module to skills-based architecture
- Refactor MCP server: extract tools and auth into separate modules
- Add connections cache, custom AI provider support
- Update prisma schema and generated client
- Various UI/UX improvements and i18n updates
- Add service worker for PWA support

Made-with: Cursor

.cursor/skills/bmad-agent-tech-writer/explain-concept.md

@@ -0,0 +1,20 @@
+---
+name: explain-concept
+description: Create clear technical explanations with examples
+menu-code: EC
+---
+
+# Explain Concept
+
+Create a clear technical explanation with examples and diagrams for a complex concept.
+
+## Process
+
+1. **Understand the concept** — Clarify what needs to be explained and the target audience
+2. **Structure** — Break it down into digestible sections using a task-oriented approach
+3. **Illustrate** — Include code examples and Mermaid diagrams where helpful
+4. **Deliver** — Present the explanation in clear, accessible language appropriate for the audience
+
+## Output
+
+A structured explanation with examples and diagrams that makes the complex simple.