feat(cli): add folders as branch-specific items

Folders can now be configured as branch-specific items in wmill.yaml:

```yaml
gitBranches:
  staging:
    specificItems:
      folders:
        - "f/env_*"
        - "f/config"
```

Branch-specific folder format: f/folder/folder.branchName.meta.yaml
(consistent with other item types where branch goes before the type suffix)

Example:
- Base: f/env_staging/folder.meta.yaml
- Branch-specific: f/env_staging/folder.main.meta.yaml

Changes:
- Add `folders?: string[]` to SpecificItemsConfig
- Add folder handling in toBranchSpecificPath()
- Add folder handling in fromBranchSpecificPath()
- Add folder pattern matching in isSpecificItem()
- Add folder detection in isBranchSpecificFile()
- Add folder detection in isCurrentBranchFile()
- Add 13 new tests for folder functionality

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

cli/src/core/specific_items.ts

@@ -8,6 +8,7 @@ export interface SpecificItemsConfig {
   variables?: string[];
   resources?: string[];
   triggers?: string[];
+  folders?: string[];
 }
 
 // Define all branch-specific file types (computed lazily)
@@ -142,6 +143,16 @@ export function isSpecificItem(path: string, specificItems: SpecificItemsConfig
     return specificItems.triggers ? matchesPatterns(path, specificItems.triggers) : false;
   }
 
+  // Check for folder meta files
+  if (path.endsWith('/folder.meta.yaml')) {
+    if (specificItems.folders) {
+      // Match against the folder path (without /folder.meta.yaml)
+      const folderPath = path.slice(0, -'/folder.meta.yaml'.length);
+      return matchesPatterns(folderPath, specificItems.folders);
+    }
+    return false;
+  }
+
   // Check for resource files using the standard detection function
   if (isFileResource(path)) {
     // Extract the base path without the file extension to match against patterns
@@ -159,6 +170,20 @@ export function isSpecificItem(path: string, specificItems: SpecificItemsConfig
  * Convert a base path to a branch-specific path
  */
 export function toBranchSpecificPath(basePath: string, branchName: string): string {
+  // Sanitize branch name to be filesystem-safe
+  const sanitizedBranchName = branchName.replace(/[\/\\:*?"<>|.]/g, '_');
+
+  // Warn about potential collisions if sanitization occurred
+  if (sanitizedBranchName !== branchName) {
+    console.warn(`Warning: Branch name "${branchName}" contains filesystem-unsafe characters (/ \\ : * ? " < > | .) and was sanitized to "${sanitizedBranchName}". This may cause collisions with other similarly named branches.`);
+  }
+
+  // Check for folder meta file pattern: folder.meta.yaml -> folder.branchName.meta.yaml
+  if (basePath.endsWith('/folder.meta.yaml')) {
+    const pathWithoutMeta = basePath.substring(0, basePath.length - '/folder.meta.yaml'.length);
+    return `${pathWithoutMeta}/folder.${sanitizedBranchName}.meta.yaml`;
+  }
+
   // Check for resource file pattern (e.g., .resource.file.ini)
   const resourceFileMatch = basePath.match(/^(.+?)(\.resource\.file\..+)$/);
 
@@ -178,14 +203,6 @@ export function toBranchSpecificPath(basePath: string, branchName: string): stri
     pathWithoutExtension = basePath.substring(0, basePath.length - extension.length);
   }
 
-  // Sanitize branch name to be filesystem-safe
-  const sanitizedBranchName = branchName.replace(/[\/\\:*?"<>|.]/g, '_');
-
-  // Warn about potential collisions if sanitization occurred
-  if (sanitizedBranchName !== branchName) {
-    console.warn(`Warning: Branch name "${branchName}" contains filesystem-unsafe characters (/ \\ : * ? " < > | .) and was sanitized to "${sanitizedBranchName}". This may cause collisions with other similarly named branches.`);
-  }
-
   return `${pathWithoutExtension}.${sanitizedBranchName}${extension}`;
 }
 
@@ -197,7 +214,13 @@ export function fromBranchSpecificPath(branchSpecificPath: string, branchName: s
   const sanitizedBranchName = branchName.replace(/[\/\\:*?"<>|.]/g, '_');
   const escapedBranchName = sanitizedBranchName.replace(/[.*+?^${}()|[\]\\]/g, '\\$&');
 
-  // Check for resource file pattern first
+  // Check for folder meta file pattern: /folder.branchName.meta.yaml -> /folder.meta.yaml
+  const folderPattern = new RegExp(`/folder\\.${escapedBranchName}\\.meta\\.yaml$`);
+  if (folderPattern.test(branchSpecificPath)) {
+    return branchSpecificPath.replace(folderPattern, '/folder.meta.yaml');
+  }
+
+  // Check for resource file pattern
   const resourceFilePattern = new RegExp(`\\.${escapedBranchName}(\\.resource\\.file\\..+)$`);
   const resourceFileMatch = branchSpecificPath.match(resourceFilePattern);
 
@@ -283,7 +306,11 @@ export function isCurrentBranchFile(path: string, branchOverride?: string): bool
   // Use cached pattern or create and cache new one
   let pattern = branchPatternCache.get(currentBranch);
   if (!pattern) {
-    pattern = new RegExp(`\\.${escapedBranchName}\\.${buildYamlTypePattern()}\\.yaml$|\\.${escapedBranchName}\\.resource\\.file\\..+$`);
+    pattern = new RegExp(
+      `\\.${escapedBranchName}\\.${buildYamlTypePattern()}\\.yaml$|` +
+      `\\.${escapedBranchName}\\.resource\\.file\\..+$|` +
+      `/folder\\.${escapedBranchName}\\.meta\\.yaml$`
+    );
     branchPatternCache.set(currentBranch, pattern);
   }
 
@@ -296,5 +323,9 @@ export function isCurrentBranchFile(path: string, branchOverride?: string): bool
  */
 export function isBranchSpecificFile(path: string): boolean {
   const yamlTypePattern = buildYamlTypePattern();
-  return new RegExp(`\\.[^.]+\\.${yamlTypePattern}\\.yaml$|\\.[^.]+\\.resource\\.file\\..+$`).test(path);
+  return new RegExp(
+    `\\.[^.]+\\.${yamlTypePattern}\\.yaml$|` +
+    `\\.[^.]+\\.resource\\.file\\..+$|` +
+    `/folder\\.[^.]+\\.meta\\.yaml$`
+  ).test(path);
 }

cli/test/specific_items.test.ts

@@ -336,3 +336,96 @@ Deno.test("branchOverride: getSpecificItemsForCurrentBranch merges common and br
   assertEquals(result?.resources, ["shared/**"]);
   assertEquals(result?.triggers, ["dev/triggers/**"]);
 });
+
+// =============================================================================
+// FOLDER BRANCH-SPECIFIC TESTS
+// Format: f/folder/folder.branchName.meta.yaml
+// =============================================================================
+
+Deno.test("toBranchSpecificPath: converts folder meta path to branch-specific", () => {
+  // f/my_folder/folder.meta.yaml -> f/my_folder/folder.main.meta.yaml
+  const result = toBranchSpecificPath("f/my_folder/folder.meta.yaml", "main");
+  assertEquals(result, "f/my_folder/folder.main.meta.yaml");
+});
+
+Deno.test("toBranchSpecificPath: converts nested folder meta path to branch-specific", () => {
+  const result = toBranchSpecificPath("f/parent/child/folder.meta.yaml", "develop");
+  assertEquals(result, "f/parent/child/folder.develop.meta.yaml");
+});
+
+Deno.test("toBranchSpecificPath: sanitizes branch name in folder path", () => {
+  const result = toBranchSpecificPath("f/env/folder.meta.yaml", "feature/test");
+  assertEquals(result, "f/env/folder.feature_test.meta.yaml");
+});
+
+Deno.test("fromBranchSpecificPath: converts branch-specific folder back to base", () => {
+  const result = fromBranchSpecificPath("f/my_folder/folder.main.meta.yaml", "main");
+  assertEquals(result, "f/my_folder/folder.meta.yaml");
+});
+
+Deno.test("fromBranchSpecificPath: handles nested branch-specific folder", () => {
+  const result = fromBranchSpecificPath("f/parent/child/folder.develop.meta.yaml", "develop");
+  assertEquals(result, "f/parent/child/folder.meta.yaml");
+});
+
+Deno.test("fromBranchSpecificPath: handles sanitized branch names for folders", () => {
+  const result = fromBranchSpecificPath("f/env/folder.feature_test.meta.yaml", "feature/test");
+  assertEquals(result, "f/env/folder.meta.yaml");
+});
+
+Deno.test("isSpecificItem: matches folder paths with glob pattern", () => {
+  const config: SpecificItemsConfig = {
+    folders: ["f/env_*"],
+  };
+  assertEquals(isSpecificItem("f/env_staging/folder.meta.yaml", config), true);
+  assertEquals(isSpecificItem("f/env_production/folder.meta.yaml", config), true);
+  assertEquals(isSpecificItem("f/other/folder.meta.yaml", config), false);
+});
+
+Deno.test("isSpecificItem: matches folder paths with exact pattern", () => {
+  const config: SpecificItemsConfig = {
+    folders: ["f/config"],
+  };
+  assertEquals(isSpecificItem("f/config/folder.meta.yaml", config), true);
+  assertEquals(isSpecificItem("f/other/folder.meta.yaml", config), false);
+});
+
+Deno.test("isBranchSpecificFile: detects branch-specific folder files", () => {
+  assertEquals(isBranchSpecificFile("f/my_folder/folder.main.meta.yaml"), true);
+  assertEquals(isBranchSpecificFile("f/my_folder/folder.develop.meta.yaml"), true);
+  assertEquals(isBranchSpecificFile("f/nested/path/folder.staging.meta.yaml"), true);
+});
+
+Deno.test("isBranchSpecificFile: returns false for non-branch-specific folder files", () => {
+  assertEquals(isBranchSpecificFile("f/my_folder/folder.meta.yaml"), false);
+  assertEquals(isBranchSpecificFile("f/nested/path/folder.meta.yaml"), false);
+});
+
+Deno.test("isCurrentBranchFile: detects branch-specific folder for current branch", () => {
+  assertEquals(isCurrentBranchFile("f/my_folder/folder.staging.meta.yaml", "staging"), true);
+  assertEquals(isCurrentBranchFile("f/my_folder/folder.staging.meta.yaml", "production"), false);
+  assertEquals(isCurrentBranchFile("f/my_folder/folder.meta.yaml", "staging"), false);
+});
+
+Deno.test("isCurrentBranchFile: handles sanitized branch for folders", () => {
+  assertEquals(isCurrentBranchFile("f/env/folder.feature_test.meta.yaml", "feature/test"), true);
+  assertEquals(isCurrentBranchFile("f/env/folder.feature_test.meta.yaml", "feature/other"), false);
+});
+
+Deno.test("round-trip: folder meta path conversion", () => {
+  const original = "f/configs/env_folder/folder.meta.yaml";
+  const branch = "main";
+  const branchSpecific = toBranchSpecificPath(original, branch);
+  assertEquals(branchSpecific, "f/configs/env_folder/folder.main.meta.yaml");
+  const restored = fromBranchSpecificPath(branchSpecific, branch);
+  assertEquals(restored, original);
+});
+
+Deno.test("round-trip: folder meta with sanitized branch", () => {
+  const original = "f/env/folder.meta.yaml";
+  const branch = "feature/new-env";
+  const branchSpecific = toBranchSpecificPath(original, branch);
+  assertEquals(branchSpecific, "f/env/folder.feature_new-env.meta.yaml");
+  const restored = fromBranchSpecificPath(branchSpecific, branch);
+  assertEquals(restored, original);
+});