Messages : types, réponses, sauts de ligne, data volume

- HomeMessages : type pill (Réaction/Question/Suggestion/Retour) + sélecteur dans le formulaire (sans Réaction)
- HomeMessages : white-space: pre-line sur les messages
- Page /messages : type pill + white-space: pre-line (idem home)
- Admin : badge type coloré + sélecteur d'édition + formulaire réponse
- API : type et reply dans PUT ; readDataYaml/writeDataYaml (data/ volume Docker)
- main.css : overrides light mode text-white/55, /75, /90

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

server/utils/content.ts

@@ -1,8 +1,10 @@
-import { readFile, writeFile } from 'node:fs/promises'
+import { readFile, writeFile, mkdir } from 'node:fs/promises'
+import { existsSync } from 'node:fs'
 import { join } from 'node:path'
 import yaml from 'yaml'
 
 const dataDir = join(process.cwd(), 'site')
+const runtimeDataDir = join(process.cwd(), 'data')
 
 const cache = new Map<string, { data: unknown; mtime: number }>()
 
@@ -35,3 +37,19 @@ export function invalidateCache(relativePath?: string): void {
     cache.clear()
   }
 }
+
+// Runtime data — stored in data/ (Docker volume, never overwritten by deploys)
+
+export async function readDataYaml<T = unknown>(relativePath: string, defaultValue: T): Promise<T> {
+  const filePath = join(runtimeDataDir, relativePath)
+  if (!existsSync(filePath)) return defaultValue
+  const raw = await readFile(filePath, 'utf-8')
+  return yaml.parse(raw) as T
+}
+
+export async function writeDataYaml(relativePath: string, data: unknown): Promise<void> {
+  await mkdir(runtimeDataDir, { recursive: true })
+  const filePath = join(runtimeDataDir, relativePath)
+  const raw = yaml.stringify(data, { lineWidth: 120 })
+  await writeFile(filePath, raw, 'utf-8')
+}