fix(manifest): restore valid plugin metadata structure (#5)

## Summary

Restore the corrupted manifest.json file to valid JSON with proper
plugin metadata.

## What Changed

The manifest.json file was corrupted (contained only "2.0.0" as plain
text instead of valid JSON). This prevented the build from succeeding
and would break plugin installation.

## What This Fixes

- ✅ Restores valid JSON structure with all required plugin metadata
- ✅ Includes correct plugin ID, name, version, and description
- ✅ Restores author information and funding URLs
- ✅ Enables successful build (`mise run build` now passes)

## Verification

- [x] Build succeeds: `dist/main.js` and `dist/manifest.json` created
- [x] No TypeScript errors
- [x] All tests passing (13/13)
- [x] Git status clean

## Related Issues

Fixes build pipeline corruption discovered during Story 4.5.1 code
review.

Co-authored-by: Development <development@local>

Author: airtonix

manifest.json

@@ -1 +1,11 @@
-2.0.0
+{
+  "id": "obsidian-kanban-bases",
+  "name": "Kanban Bases View",
+  "version": "2.0.0",
+  "minAppVersion": "1.10.3",
+  "description": "A kanban view for Obsidian database bases with drag-drop support and virtual scrolling",
+  "author": "zenobi-us",
+  "authorUrl": "https://github.com/zenobi-us",
+  "fundingUrl": "https://github.com/sponsors/zenobi-us",
+  "isDesktopOnly": false
+}