docs: update Bruno terminology to OpenCollection YAML format

Update all references from "Bruno DSL .bru files" to "Bruno OpenCollection YAML .yml files" to reflect the current Bruno format. This includes:

- PROJECT_GUIDELINES.md: Update API testing requirements
- README.md: Update command examples
- TEST_DATA.md: Update test data references
- docs/contributing/development.md: Update API testing section
- docs/developer/api-reference.md: Update Bruno testing documentation
- docs/developer/collections-api.md: Update test file references
- scripts/README.md: Update validation script documentation
- scripts/verify-guidelines.sh: Update file extension check (.bru → .yml)
- bruno/opencollection.yml: Rename collection from "Untitled Collection" to "Bookhoard"

PROJECT_GUIDELINES.md

@@ -128,7 +128,7 @@ VERIFY → Compile successfully
 - ✅ Stop building server binaries - everything goes through containers
 
 ### API Changes (Full-Stack Tasks Only)
-- ✅ Include **Bruno DSL .bru requests** with all API documentation
+- ✅ Include **Bruno OpenCollection YAML requests** with all API documentation
 - ✅ Tests must be **comprehensive and cover three contexts**: no user, user, and admin
 - ✅ Maintain backward compatibility for mobile apps and external consumers
 
@@ -204,7 +204,7 @@ VERIFY → Compile successfully
 | **Quick start/setup** | `README.md` | Installation, environment setup, first-run |
 | **Breaking changes** | Both `README.md` and relevant `docs/` | Migration guides, deprecation notices |
 | **Bug fixes** | Update relevant `docs/` only if user-visible | Clarifications, troubleshooting additions |
-| **Bruno API tests** | `.bru` files alongside code | API contract testing, examples |
+| **Bruno OpenCollection YAML tests** | `.yml` files in bruno folder in appropriate folder/sub-folder | API contract testing, examples |
 
 **Documentation Update Workflow**:
 1. **Identify the audience** (end users, developers, API consumers)
@@ -212,7 +212,7 @@ VERIFY → Compile successfully
 3. **Update documentation** before or with code changes
 4. **Verify documentation renders** at `/docs` endpoint
 5. **Test search** finds new/updated content
-6. **For API changes**: Update both `docs/developer/api/` files AND Bruno `.bru` files
+6. **For API changes**: Update both `docs/developer/api/` files AND Bruno OpenCollection YAML `.yml` files
 7. **Commit separately** with clear message: `docs: <description>`
 
 **When in doubt**:
@@ -312,7 +312,7 @@ git checkout -- internal/handlers/auth.go
   - [ ] New endpoints → Create new `.md` file in `docs/developer/api/`
   - [ ] API behavior → Update existing `docs/developer/api/` files
   - [ ] Breaking changes → Both `README.md` + relevant `docs/`
-  - [ ] Bruno `.bru` files → Update/create alongside API changes
+  - [ ] Bruno OpenCollection YAML `.yml` files → Update/create alongside API changes
 
 ### During Schema Changes (Full-Stack Only)
 - [ ] Read current schema completely
@@ -336,7 +336,7 @@ git checkout -- internal/handlers/auth.go
 - [ ] Verify database has new schema (check column types, indexes, etc.)
 
 ### After API Changes
-- [ ] Create/update Bruno DSL .bru requests
+- [ ] Create/update Bruno OpenCollection YAML requests
 - [ ] Test with no user context
 - [ ] Test with regular user context
 - [ ] Test with admin context
@@ -352,7 +352,7 @@ git checkout -- internal/handlers/auth.go
 - [ ] Verify logical commit structure
 - [ ] **Update documentation** (see Documentation section):
   - [ ] User-facing changes → `docs/user/`
-  - [ ] API changes → `docs/developer/api/` + Bruno `.bru` files
+  - [ ] API changes → `docs/developer/api/` + Bruno OpenCollection YAML `.yml` files
   - [ ] Setup/onboarding → `README.md`
   - [ ] Development changes → `docs/contributing/`
 - [ ] **Verify docs render** at `/docs` endpoint

README.md

@@ -133,7 +133,7 @@ make test-all
 # Run integration tests (with test mode)
 make test-integration
 
-# Run Bruno API tests
+# Run Bruno OpenCollection YAML API tests
 npm install -g @usebruno/cli
 bruno run
 ```

TEST_DATA.md

@@ -20,7 +20,7 @@ This is the primary test user used in most integration tests.
 
 **Used in:**
 - Go Tests: `cmd/server/tests/test_helpers.go` (getTestUserID, loginTestUser)
-- Bruno: `user/auth/Login User.bru`, `user/auth/Register User.bru`
+- Bruno: `user/auth/Login User.yml`, `user/auth/Register User.yml`
 
 **Notes:**
 - Automatically created if doesn't exist
@@ -58,7 +58,7 @@ Used for testing admin creation restrictions and multi-admin scenarios.
 ```
 
 **Used in:**
-- Bruno: `user/admin/Register Admin User.bru`
+- Bruno: `user/admin/Register Admin User.yml`
 
 ## Test Libraries
 

bruno/opencollection.yml

@@ -1,7 +1,7 @@
 opencollection: 1.0.0
 
 info:
-  name: Untitled Collection
+  name: Bookhoard
 config:
   proxy:
     inherit: true
@@ -21,8 +21,8 @@ request:
 
 docs:
   content: |-
-    # Bruno API Tests for Bookhoard
+    # Bruno OpenCollection YAML API Tests for Bookhoard
-    This directory contains Bruno collection for testing the Bookhoard API with comprehensive REST documentation.
+    This directory contains Bruno OpenCollection YAML format tests for testing the Bookhoard API with comprehensive REST documentation.
      Setup
     1. Install Bruno: https://www.usebruno.com/
     2. Open Bruno and import this collection folder

docs/contributing/development.md

@@ -256,7 +256,7 @@ TEST_MODE=true RATE_LIMIT_ENABLED=false go test ./cmd/server/tests -v
 go test ./cmd/server/tests -run TestAuth -v
 ```
 
-### API Testing with Bruno
+### API Testing with Bruno OpenCollection YAML
 
 ```bash
 # Install Bruno CLI

docs/developer/api-reference.md

@@ -1606,10 +1606,10 @@ bruno/
 ├── sync-kobo/              # Kobo sync protocol
 ├── conflicts/               # Conflict resolution
 ├── queue/                   # Sync queue management
-└── collection.bru           # Main collection file
+└── collection.yml           # Main collection file
 ```
 
-## Testing with Bruno
+## Testing with Bruno OpenCollection YAML
 
 Install Bruno CLI:
 ```bash

docs/developer/collections-api.md

@@ -467,20 +467,20 @@ X-RateLimit-Reset: 1643723400
 
 ---
 
-## Bruno Tests
+## Bruno OpenCollection YAML Tests
 
 Complete API tests available in `bruno/collections/`:
 
-- `Get Collections.bru`
+- `Get Collections.yml`
-- `Create Collection.bru`
+- `Create Collection.yml`
-- `Get Collection.bru`
+- `Get Collection.yml`
-- `Update Collection.bru`
+- `Update Collection.yml`
-- `Delete Collection.bru`
+- `Delete Collection.yml`
-- `Add Books to Collection.bru`
+- `Add Books to Collection.yml`
-- `Remove Book from Collection.bru`
+- `Remove Book from Collection.yml`
-- `Get Book Collections.bru`
+- `Get Book Collections.yml`
-- `Test Collection Rules.bru`
+- `Test Collection Rules.yml`
-- `Bulk Remove Books.bru`
+- `Bulk Remove Books.yml`
 
 Run tests:
 ```bash

scripts/README.md

@@ -259,22 +259,22 @@ templates/... (truncated, first 10 shown)
 - `make verify-quick`: Runs critical-only validation
 - Fixed naming confusion (previously ran quick version for both targets)
 
-### Bruno API Tests Validation:
+### Bruno OpenCollection YAML Validation:
-- Counts Bruno `.bru` test files in `bruno/` directory
+- Counts Bruno OpenCollection YAML `.yml` test files in `bruno/` directory
 - Compares against API documentation file count in `docs/api/`
 - Flags insufficient coverage for human review
 - Ensures API documentation and test coverage stay synchronized
 
-## Bruno API Tests Explained
+## Bruno OpenCollection YAML Explained
 
 ### Purpose:
-Bruno v3.0 is an API testing tool that uses `.bru` files to define:
+Bruno is an API testing tool that uses OpenCollection YAML format (`.yml` files) to define:
 - API requests and responses
 - Test cases and validation
 - Contract testing examples
 
 ### Verification Logic:
-1. **Counts Test Files**: Scans `bruno/` directory for `.bru` files
+1. **Counts Test Files**: Scans `bruno/` directory for `.yml` files
 2. **Counts API Docs**: Scans `docs/api/` for `.md` files  
 3. **Compares Coverage**: Ensures test files >= documentation files
 4. **Flags Gaps**: Human review for insufficient test coverage
@@ -282,7 +282,7 @@ Bruno v3.0 is an API testing tool that uses `.bru` files to define:
 ### Example Scenario:
 ```
 Developer adds: docs/api/users/login.md
-Should also add: bruno/user/auth/Login User.bru
+Should also add: bruno/user/auth/Login User.yml
 Verification catches: API docs exist but no test file
 ```
 

scripts/verify-guidelines.sh

@@ -477,8 +477,8 @@ fi
 ###############################################################################
 section "Documentation: Bruno API Tests"
 
-echo "Checking Bruno API test files..."
+echo "Checking Bruno OpenCollection YAML test files..."
-BRUNO_FILES=$(find bruno -name "*.bru" 2>/dev/null | wc -l)
+BRUNO_FILES=$(find bruno -name "*.yml" 2>/dev/null | wc -l)
 if [ "$BRUNO_FILES" -gt 0 ]; then
     success_msg "Found $BRUNO_FILES Bruno test files"
 else