fix: auto-resolve extensionless URLs to processor files

Two changes:
1. processorResource._handle: when url2file returns None, try appending
   each processor extension (.dspy, .ui, .tmpl) to find a match.
   After finding a processor, override its real_path if fallback was used.
2. baseProcessor.set_run_env: only recalculate real_path if not already
   set, preserving the fallback value from processorResource.

Fixes bricks i18n.js requesting /i18n_getmsgs without .dspy suffix.

ahserver/baseProcessor.py

@@ -68,6 +68,8 @@ class BaseProcessor:
 		if self.env_set:
 			self.run_ns['params_kw'].update(params)
 			return
+		# Only calculate real_path if not already set (e.g., by fallback in _handle)
+		if not hasattr(self, 'real_path') or self.real_path is None:
 			self.real_path = self.resource.url2file(request.path)
 		g = ServerEnv()
 		self.run_ns = DictObject()

ahserver/processorResource.py

@@ -377,6 +377,9 @@ class ProcessorResource(StaticResource,Url2File):
 		request['port'] = config.website.port
 		processor = self.url2processor(request, str(request.url), self.request_filename)
 		if processor:
+			# Fix real_path when fallback added an extension
+			if self.request_filename and (not hasattr(processor, 'real_path') or not processor.real_path):
+				processor.real_path = self.request_filename
 			ret = await processor.handle(request)
 			return ret