feat: rename keep-notes to memento-note, migrate to PostgreSQL, fix MCP bugs

- Rename directory keep-notes -> memento-note with all code references
- Prisma: SQLite -> PostgreSQL (both app and MCP server schemas)
- Sync MCP schema with main app (add missing fields, relations, indexes)
- Delete 17 SQLite migrations (clean slate for PostgreSQL)
- Remove SQLite dependencies (@libsql/client, better-sqlite3, etc.)
- Fix MCP server: hardcoded Windows DB paths -> DATABASE_URL env var
- Fix MCP server: .dockerignore excluded index-sse.js (SSE mode broken)
- MCP Dockerfile: node:20 -> node:22
- Docker Compose: add postgres service, remove SQLite volume
- Generate favicon.ico, icon-192.png, icon-512.png, apple-icon.png
- Update layout.tsx icons and manifest.json for PNG icons
- Update all .env files for PostgreSQL
- Rewrite README.md with updated sections
- Remove mcp-server/node_modules and prisma/client-generated from git tracking

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

memento-note/playwright-report/data/f9c0e00aedaecd19abca15658d106a76bce06d86.md

@@ -0,0 +1,24 @@
+# Page snapshot
+
+```yaml
+- generic [active] [ref=e1]:
+  - main [ref=e4]:
+    - generic [ref=e7]:
+      - heading "Sign in to your account" [level=1] [ref=e8]
+      - generic [ref=e9]:
+        - generic [ref=e10]:
+          - generic [ref=e11]: Email
+          - textbox "Email" [ref=e13]:
+            - /placeholder: Enter your email address
+        - generic [ref=e14]:
+          - generic [ref=e15]: Password
+          - textbox "Password" [ref=e17]:
+            - /placeholder: Enter your password
+      - link "Forgot password?" [ref=e19] [cursor=pointer]:
+        - /url: /forgot-password
+      - button "Sign In" [ref=e20]
+  - region "Notifications alt+T"
+  - button "Open Next.js Dev Tools" [ref=e27] [cursor=pointer]:
+    - img [ref=e28]
+  - alert [ref=e31]
+```