ui: Add Thinking mode toggle with reasoning effort levels + improvements for Chat Form Add Action UI (#23434)

* feat: Add "Thinking" toggle and status icon + redesign Chat Form Actions Add panel

* test: Update test reference

* fix: Icon

* fix: E2E test command

* fix: wait for greeting h1 to be visible in e2e test

* fix: remove duplicate PDF option in attachment dropdown

* fix: use label-based group toggle to avoid stale references

* refactor: inline MCP server and tool toggles in mobile sheet

* fix: serve correct build directory in e2e playwright config

* feat: add reasoning effort levels selector in model dropdown

* feat: Reasoning effort

* refactor: Make server origin configurable via environment variable

* feat: Add chat template thinking detector utility

* feat: Add thinking support detection to models store

* refactor: Update model selector components with thinking detection and message-specific indicators

* feat: Update chat form components for model selection and thinking support

* feat: Improve Reasoning controls UI

* refactor: Apply suggestions from code review

Co-authored-by: Aleksander Grygier <aleksander.grygier@gmail.com>

* fix: Model tags

* refactor: Cleanup

* refactor: Remove unneeded components

* refactor: Cleanup

tools/ui/src/lib/services/chat.service.ts

@@ -6,6 +6,7 @@ import {
 	ATTACHMENT_LABEL_MCP_PROMPT,
 	ATTACHMENT_LABEL_MCP_RESOURCE,
 	LEGACY_AGENTIC_REGEX,
+	REASONING_EFFORT_TOKENS,
 	SETTINGS_KEYS,
 	API_CHAT,
 	API_SLOTS,
@@ -162,6 +163,8 @@ export class ChatService {
 			// Config options
 			disableReasoningParsing,
 			excludeReasoningFromContext,
+			enableThinking,
+			reasoningEffort,
 			continueFinalMessage
 		} = options;
 
@@ -243,6 +246,18 @@ export class ChatService {
 			? ReasoningFormat.NONE
 			: ReasoningFormat.AUTO;
 
+		const reasoningBudgetTokens =
+			enableThinking && reasoningEffort ? (REASONING_EFFORT_TOKENS[reasoningEffort] ?? -1) : -1;
+
+		requestBody.chat_template_kwargs = {
+			...(requestBody.chat_template_kwargs ?? {}),
+			enable_thinking: enableThinking
+		};
+
+		if (reasoningBudgetTokens >= 0) {
+			requestBody.thinking_budget_tokens = reasoningBudgetTokens;
+		}
+
 		// arms the budget sampler so reasoning can be ended at runtime via the control endpoint
 		requestBody.reasoning_control = true;