PR #543: chat UIX/UX fixes — thinking indicators, message dedup, streaming stability (JohnGuidry)

Addresses #572 (double chat responses) + #561 (stuck Thinking indicator).
Adds optimistic-message-reinject hook, vite loadEnv→process.env bridge for SSR
bearer token, dedup + streaming stability. eslint --fix on touched files
(net lint errors 1700→1588). Build GREEN, test 33 fail/694 pass (zero regressions).

vite.config.ts

@@ -88,6 +88,15 @@ async function isClaudeAgentHealthy(port = 8642): Promise<boolean> {
 
 const config = defineConfig(({ mode, command }) => {
   const env = loadEnv(mode, process.cwd(), '')
+  // Bridge loadEnv into process.env for server-side SSR runtime code that
+  // reads env vars directly from process.env (e.g. getBearerToken() in
+  // openai-compat-api.ts reads process.env.HERMES_API_TOKEN). Without this,
+  // Vite's loadEnv only populates the local `env` object — not process.env.
+  for (const key of Object.keys(env)) {
+    if (!(key in process.env)) {
+      process.env[key] = env[key]
+    }
+  }
   const claudeApiUrl = env.CLAUDE_API_URL?.trim() || 'http://127.0.0.1:8642'
   // /api/connection-status is handled by the real route file at
   // src/routes/api/connection-status.ts; the dev server no longer