chore: auto-fix Biome formatting and configure lint rules

Run biome check --write --unsafe to fix tabs, import ordering, and
non-null assertions across entire codebase. Disable a11y rules not
applicable to this single-user app. Exclude auto-generated routeTree.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

tsconfig.json

@@ -1,31 +1,31 @@
 {
-  "compilerOptions": {
-    "lib": ["ESNext", "DOM", "DOM.Iterable"],
-    "target": "ESNext",
-    "module": "ESNext",
-    "moduleDetection": "force",
-    "jsx": "react-jsx",
-    "allowJs": true,
+	"compilerOptions": {
+		"lib": ["ESNext", "DOM", "DOM.Iterable"],
+		"target": "ESNext",
+		"module": "ESNext",
+		"moduleDetection": "force",
+		"jsx": "react-jsx",
+		"allowJs": true,
 
-    "moduleResolution": "bundler",
-    "allowImportingTsExtensions": true,
-    "verbatimModuleSyntax": true,
-    "noEmit": true,
+		"moduleResolution": "bundler",
+		"allowImportingTsExtensions": true,
+		"verbatimModuleSyntax": true,
+		"noEmit": true,
 
-    "strict": true,
-    "skipLibCheck": true,
-    "noFallthroughCasesInSwitch": true,
-    "noUncheckedIndexedAccess": true,
-    "noImplicitOverride": true,
+		"strict": true,
+		"skipLibCheck": true,
+		"noFallthroughCasesInSwitch": true,
+		"noUncheckedIndexedAccess": true,
+		"noImplicitOverride": true,
 
-    "noUnusedLocals": false,
-    "noUnusedParameters": false,
-    "noPropertyAccessFromIndexSignature": false,
+		"noUnusedLocals": false,
+		"noUnusedParameters": false,
+		"noPropertyAccessFromIndexSignature": false,
 
-    "paths": {
-      "@/*": ["./src/*"]
-    },
-    "types": ["bun-types"]
-  },
-  "include": ["src", "tests"]
+		"paths": {
+			"@/*": ["./src/*"]
+		},
+		"types": ["bun-types"]
+	},
+	"include": ["src", "tests"]
 }