feat: implement experimental features system

- Add experiments.ts to manage experimental features
- Refactor experimental diff strategy into experiments system
- Add UI components for managing experimental features
- Add tests for experimental tools
- Update system prompts to handle experiments

src/shared/__tests__/modes.test.ts

@@ -14,6 +14,12 @@ describe("isToolAllowedForMode", () => {
 			roleDefinition: "You are a CSS editor",
 			groups: ["read", ["edit", { fileRegex: "\\.css$" }], "browser"],
 		},
+		{
+			slug: "test-exp-mode",
+			name: "Test Exp Mode",
+			roleDefinition: "You are an experimental tester",
+			groups: ["read", "edit", "browser"],
+		},
 	]
 
 	it("allows always available tools", () => {
@@ -240,6 +246,87 @@ describe("isToolAllowedForMode", () => {
 
 		expect(isToolAllowedForMode("write_to_file", "markdown-editor", customModes, toolRequirements)).toBe(false)
 	})
+
+	describe("experimental tools", () => {
+		it("disables tools when experiment is disabled", () => {
+			const experiments = {
+				search_and_replace: false,
+				insert_code_block: false,
+			}
+
+			expect(
+				isToolAllowedForMode(
+					"search_and_replace",
+					"test-exp-mode",
+					customModes,
+					undefined,
+					undefined,
+					experiments,
+				),
+			).toBe(false)
+
+			expect(
+				isToolAllowedForMode(
+					"insert_code_block",
+					"test-exp-mode",
+					customModes,
+					undefined,
+					undefined,
+					experiments,
+				),
+			).toBe(false)
+		})
+
+		it("allows tools when experiment is enabled", () => {
+			const experiments = {
+				search_and_replace: true,
+				insert_code_block: true,
+			}
+
+			expect(
+				isToolAllowedForMode(
+					"search_and_replace",
+					"test-exp-mode",
+					customModes,
+					undefined,
+					undefined,
+					experiments,
+				),
+			).toBe(true)
+
+			expect(
+				isToolAllowedForMode(
+					"insert_code_block",
+					"test-exp-mode",
+					customModes,
+					undefined,
+					undefined,
+					experiments,
+				),
+			).toBe(true)
+		})
+
+		it("allows non-experimental tools when experiments are disabled", () => {
+			const experiments = {
+				search_and_replace: false,
+				insert_code_block: false,
+			}
+
+			expect(
+				isToolAllowedForMode("read_file", "markdown-editor", customModes, undefined, undefined, experiments),
+			).toBe(true)
+			expect(
+				isToolAllowedForMode(
+					"write_to_file",
+					"markdown-editor",
+					customModes,
+					undefined,
+					{ path: "test.md" },
+					experiments,
+				),
+			).toBe(true)
+		})
+	})
 })
 
 describe("FileRestrictionError", () => {