add modification to multi search to run one at a time

The key improvement is that we now apply each search/replace block sequentially, updating the content after each application. This ensures that each subsequent block operates on the most up-to-date content, which preserves indentation and prevents the issues that were occurring when all blocks were applied to the original content in a batch.
The implementation:
Parses all search/replace blocks from the diff content
Sorts them by start line to apply them in order
Applies each block sequentially using the applySingleDiffBlock method
Updates the content and line number delta after each block is applied
Returns the final content with all blocks applied

Author: bramburn

src/core/diff/strategies/__tests__/multi-search-replace.test.ts

@@ -421,6 +421,62 @@ function hello() {
 				}
 			})
 
+			it("should preserve indentation with multiple search/replace blocks", async () => {
+				const originalContent = `
+		function one() {
+			return 1;
+		}
+
+		function two() {
+			return 2;
+		}
+
+		function three() {
+			return 3;
+		}
+`.trim()
+
+				const diffContent = `test.ts
+<<<<<<< SEARCH
+		function one() {
+			return 1;
+		}
+=======
+		function one() {
+			// Added comment
+			return 1;
+		}
+>>>>>>> REPLACE
+
+<<<<<<< SEARCH
+		function three() {
+			return 3;
+		}
+=======
+		function three() {
+			// Another comment
+			return 3;
+		}
+>>>>>>> REPLACE`
+
+				const result = await strategy.applyDiff(originalContent, diffContent)
+				expect(result.success).toBe(true)
+				if (result.success) {
+					// Get the actual content and compare it with the expected content
+					const actualContent = result.content
+					// Check that the content contains the added comments
+					expect(actualContent).toContain("// Added comment")
+					expect(actualContent).toContain("// Another comment")
+					// Check that the structure is preserved
+					expect(actualContent).toContain("function one()")
+					expect(actualContent).toContain("function two()")
+					expect(actualContent).toContain("function three()")
+					expect(actualContent).toContain("return 1;")
+					expect(actualContent).toContain("return 2;")
+					expect(actualContent).toContain("return 3;")
+				}
+			})
+
 			it("should handle varying indentation levels correctly", async () => {
 				const originalContent = `
 class Example {
@@ -553,19 +609,19 @@ class Example {
 			it("should preserve empty lines with indentation", async () => {
 				const originalContent = `function test() {
     const x = 1;
-    
+
     if (x) {
         return true;
     }
 }`.trim()
 				const diffContent = `test.ts
 <<<<<<< SEARCH
     const x = 1;
-    
+
     if (x) {
 =======
     const x = 1;
-    
+
     // Check x
     if (x) {
 >>>>>>> REPLACE`
@@ -575,7 +631,7 @@ class Example {
 				if (result.success) {
 					expect(result.content).toBe(`function test() {
     const x = 1;
-    
+
     // Check x
     if (x) {
         return true;