Refactor Reconciler tests and update path handling logic

- Updated test descriptions in `diff.spec.lua` and `diff.stress.spec.lua` to reflect changes in behavior regarding duplicate-named children in both real and virtual DOM contexts.
- Adjusted assertions to ensure that duplicate-named children are correctly removed or added based on the new matching logic.
- Refactored `hydrate.lua` and `matching.lua` to streamline the matching process by removing unnecessary parameters, enhancing clarity and maintainability.
- Updated metadata references in various test files to include the `.model.json5` extension for consistency in path handling.

These changes improve the accuracy of reconciliation tests and enhance the overall robustness of the Reconciler's path handling logic.

plugin/src/Reconciler/diff.spec.lua

@@ -276,7 +276,7 @@ return function()
 	end)
 
 	describe("duplicate-named siblings", function()
-		it("should skip real DOM children with duplicate names", function()
+		it("should remove real DOM children with duplicate names when not in virtual DOM", function()
 			local knownInstances = InstanceMap.new()
 			local virtualInstances = {
 				ROOT = {
@@ -305,11 +305,11 @@ return function()
 
 			assert(ok, tostring(patch))
 
-			-- Duplicate-named children should be skipped (not removed)
-			assert(isEmpty(patch.removed))
+			-- Duplicate-named children should be removed (matching handles pairing)
+			expect(#patch.removed).to.equal(2)
 		end)
 
-		it("should skip virtual children with duplicate names among siblings", function()
+		it("should add virtual children with duplicate names among siblings", function()
 			local knownInstances = InstanceMap.new()
 			local virtualInstances = {
 				ROOT = {
@@ -340,8 +340,8 @@ return function()
 
 			assert(ok, tostring(patch))
 
-			-- Duplicate-named virtual children should not be added
-			assert(isEmpty(patch.added))
+			-- Duplicate-named virtual children should be added (matching handles pairing)
+			expect(size(patch.added)).to.equal(2)
 		end)
 	end)
 

plugin/src/Reconciler/diff.stress.spec.lua

@@ -239,9 +239,8 @@ return function()
 			local ok, patch = diff(instanceMap, virtualInstances, rootId)
 
 			expect(ok).to.equal(true)
-			-- Duplicates should NOT be marked for removal
-			-- Only if they had unique names would they be candidates
-			expect(#patch.removed).to.equal(0)
+			-- Duplicates should be marked for removal (matching handles pairing)
+			expect(#patch.removed).to.equal(2)
 
 			instanceMap:stop()
 		end)
@@ -290,9 +289,9 @@ return function()
 			local ok, patch = diff(instanceMap, virtualInstances, rootId)
 
 			expect(ok).to.equal(true)
-			-- Neither duplicate should be added since the path is ambiguous
-			expect(patch.added[dup1Id]).to.equal(nil)
-			expect(patch.added[dup2Id]).to.equal(nil)
+			-- Both duplicates should be added (matching handles pairing)
+			expect(patch.added[dup1Id]).to.be.ok()
+			expect(patch.added[dup2Id]).to.be.ok()
 
 			instanceMap:stop()
 		end)
@@ -350,8 +349,8 @@ return function()
 			local ok, patch = diff(instanceMap, virtualInstances, rootId)
 
 			expect(ok).to.equal(true)
-			-- Grandchild should also NOT be added since its parent is ambiguous
-			expect(patch.added[grandchildId]).to.equal(nil)
+			-- Grandchild should be added along with its parent (matching handles pairing)
+			expect(patch.added[grandchildId]).to.be.ok()
 
 			instanceMap:stop()
 		end)

plugin/src/Reconciler/hydrate.lua

@@ -41,7 +41,7 @@ local function hydrate(instanceMap, virtualInstances, rootId, rootInstance)
 	end
 
 	-- Use the 3-pass matching algorithm to pair virtual ↔ studio children
-	local result = Matching.matchChildren(validVirtualIds, existingChildren, virtualInstances, instanceMap)
+	local result = Matching.matchChildren(validVirtualIds, existingChildren, virtualInstances)
 
 	-- Recursively hydrate matched pairs
 	for _, pair in result.matched do

plugin/src/Reconciler/matching.lua

@@ -114,8 +114,7 @@ local Matching = {}
 function Matching.matchChildren(
 	virtualChildren: { string },
 	studioChildren: { Instance },
-	virtualInstances: { [string]: any },
-	instanceMap: any
+	virtualInstances: { [string]: any }
 )
 	local matched: { { virtualId: string, studioInstance: Instance } } = {}
 	local remainingVirtual: { string } = table.clone(virtualChildren)
@@ -344,7 +343,7 @@ function Matching._computeChangeCount(
 	end
 
 	-- Recursive: match children and sum costs
-	local childResult = Matching.matchChildren(validVChildren, studioKids, virtualInstances, nil)
+	local childResult = Matching.matchChildren(validVChildren, studioKids, virtualInstances)
 
 	-- Matched children: recursively score each pair
 	for _, pair in childResult.matched do