Add OpenRouter chat provider; fix Windows load errors (0.17.0).

- OpenRouter as an alternative chat provider: server-side API key
  (settings.json or OPENROUTER_API_KEY), model list with vision marks and
  filter, SSE streaming, images as data URLs. Memory embeddings stay on Ollama;
  park/warm LLM are no-ops for the remote provider.
- AssistentSaveKnowledgeAttach: JArray param is not supported by SwarmUI API
  reflection and aborted registration of every later API call; use string[].
- SQLite bootstrap: preload native e_sqlite3 for the current OS/arch
  (win/osx/linux) and resolve DllImport to it.
- settings.json: shared-read + atomic write with retry to avoid Windows
  sharing violations.
- csproj: fix MSB4012 in the native SQLite copy target.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

AssistentChatPipeline.cs

@@ -253,7 +253,9 @@ public partial class SwarmAssistentExtension
             {
                 await onHopStart(hop);
             }
-            (reply, lastRaw) = await CallOllamaChat(root, modelName, messages, stream: onDelta is not null, onDelta, pid);
+            (reply, lastRaw) = UseOpenRouter()
+                ? await CallOpenRouterChat(modelName, messages, stream: onDelta is not null, onDelta, pid)
+                : await CallOllamaChat(root, modelName, messages, stream: onDelta is not null, onDelta, pid);
             if (slimUtility)
             {
                 break;