Merge remote-tracking branch 'origin/master' into gitea/feature/end

Resolved conflicts taking origin/master (v0.5.55) as canonical, with local
features re-applied:
- runtime log level (LOG_LEVEL env + dashboard Settings → Logging, applied
  immediately and persisted across restarts)
- free/noAuth provider enable/disable toggle via providerStrategies.enabled
- parallel model testing (Test All Models / Test Selected Keys)

open-sse/translator/request/claude-to-openai.js

@@ -129,14 +129,15 @@ function fixMissingToolResponsesOpenAI(messages) {
   }
 }
 
-// Wrap mid-conversation system text so it ends as a user turn (avoids Anthropic prefill 400)
+// Wrap mid-conversation system text so it ends as a user turn (avoids Anthropic prefill 400).
+// Uses <instructions> tags that Claude models treat as authoritative directives.
 function systemReminderText(content) {
   const parts = Array.isArray(content)
     ? content.filter(c => c?.type === CLAUDE_BLOCK.TEXT).map(c => c.text || "")
     : [typeof content === "string" ? content : ""];
   const text = parts.filter(Boolean).join("\n");
   if (!text.trim()) return "";
-  return `<system-reminder>\n${text}\n</system-reminder>`;
+  return `<instructions>\n${text}\n</instructions>`;
 }
 
 // Convert single Claude message - returns single message or array of messages