chore: add prettier + enforce LF line endings

- Add .prettierrc (double quotes, 2-space, trailing comma es5, LF, 100 cols)
- Add .prettierignore (excludes node_modules, .next, server/, lock files)
- Add .editorconfig (LF + per-language indent rules for all editors)
- Expand .gitattributes to cover all text file types with eol=lf
- Add prettier@^3.5.3 devDep at workspace root with format/format:check scripts
- Add format/format:check scripts to web/package.json

pnpm-lock.yaml

@@ -6,7 +6,11 @@ settings:
 
 importers:
 
-  .: {}
+  .:
+    devDependencies:
+      prettier:
+        specifier: ^3.5.3
+        version: 3.8.3
 
   web:
     dependencies:
@@ -516,6 +520,11 @@ packages:
     resolution: {integrity: sha512-W62t/Se6rA0Az3DfCL0AqJwXuKwBeYg6nOaIgzP+xZ7N5BFCI7DYi1qs6ygUYT6rvfi6t9k65UMLJC+PHZpDAA==}
     engines: {node: ^10 || ^12 || >=14}
 
+  prettier@3.8.3:
+    resolution: {integrity: sha512-7igPTM53cGHMW8xWuVTydi2KO233VFiTNyF5hLJqpilHfmn8C8gPf+PS7dUT64YcXFbiMGZxS9pCSxL/Dxm/Jw==}
+    engines: {node: '>=14'}
+    hasBin: true
+
   react-dom@19.1.0:
     resolution: {integrity: sha512-Xs1hdnE+DyKgeHJeJznQmYMIBG3TKIHJJT95Q58nHLSrElKlGQqDTR2HQ9fx5CN/Gk6Vh/kupBTDLU11/nDk/g==}
     peerDependencies:
@@ -917,6 +926,8 @@ snapshots:
       picocolors: 1.1.1
       source-map-js: 1.2.1
 
+  prettier@3.8.3: {}
+
   react-dom@19.1.0(react@19.1.0):
     dependencies:
       react: 19.1.0