feat: add agent schema validation with comprehensive testing

Introduce automated validation for agent YAML files using Zod to ensure
schema compliance across all agent definitions. This feature validates
17 agent files across core and module directories, catching structural
errors and maintaining consistency.

Schema Validation (tools/schema/agent.js):
- Zod-based schema validating metadata, persona, menu, prompts, and critical actions
- Module-aware validation: module field required for src/modules/**/agents/,
  optional for src/core/agents/
- Enforces kebab-case unique triggers and at least one command target per menu item
- Validates persona.principles as array (not string)
- Comprehensive refinements for data integrity

CLI Validator (tools/validate-agent-schema.js):
- Scans src/{core,modules/*}/agents/*.agent.yaml
- Parses with js-yaml and validates using Zod schema
- Reports detailed errors with file paths and field paths
- Exits 1 on failures, 0 on success
- Accepts optional project_root parameter for testing

Testing (679 lines across 3 test files):
- test/test-cli-integration.sh: CLI behavior and error handling tests
- test/unit-test-schema.js: Direct schema validation unit tests
- test/test-agent-schema.js: Comprehensive fixture-based tests
- 50 test fixtures covering valid and invalid scenarios
- ESLint configured to support CommonJS test files
- Prettier configured to ignore intentionally broken fixtures

CI Integration (.github/workflows/lint.yaml):
- Renamed from format-check.yaml to lint.yaml
- Added schema-validation job running npm run validate:schemas
- Runs in parallel with prettier and eslint jobs
- Validates on all pull requests

Data Cleanup:
- Fixed src/core/agents/bmad-master.agent.yaml: converted persona.principles
  from string to array format

Documentation:
- Updated schema-classification.md with validation section
- Documents validator usage, enforcement rules, and CI integration

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

test/fixtures/agent-schema/invalid/critical-actions/actions-as-string.agent.yaml

@@ -0,0 +1,26 @@
+# Test: critical_actions as non-array
+# Expected: FAIL
+# Error code: invalid_type
+# Error path: agent.critical_actions
+# Error expected: array
+
+agent:
+  metadata:
+    id: actions-string
+    name: Actions String
+    title: Actions String
+    icon: ❌
+
+  persona:
+    role: Test agent
+    identity: Test identity
+    communication_style: Test style
+    principles:
+      - Test principle
+
+  critical_actions: This should be an array
+
+  menu:
+    - trigger: help
+      description: Show help
+      action: display_help

test/fixtures/agent-schema/invalid/critical-actions/empty-string-in-actions.agent.yaml

@@ -0,0 +1,29 @@
+# Test: critical_actions with empty strings
+# Expected: FAIL
+# Error code: custom
+# Error path: agent.critical_actions[1]
+# Error message: agent.critical_actions[] must be a non-empty string
+
+agent:
+  metadata:
+    id: empty-action-string
+    name: Empty Action String
+    title: Empty Action String
+    icon: ❌
+
+  persona:
+    role: Test agent
+    identity: Test identity
+    communication_style: Test style
+    principles:
+      - Test principle
+
+  critical_actions:
+    - Valid action
+    - "   "
+    - Another valid action
+
+  menu:
+    - trigger: help
+      description: Show help
+      action: display_help

test/fixtures/agent-schema/invalid/menu-commands/empty-command-target.agent.yaml

@@ -0,0 +1,24 @@
+# Test: Menu item with empty string command target
+# Expected: FAIL
+# Error code: custom
+# Error path: agent.menu[0].action
+# Error message: agent.menu[].action must be a non-empty string
+
+agent:
+  metadata:
+    id: empty-command
+    name: Empty Command Target
+    title: Empty Command
+    icon: ❌
+
+  persona:
+    role: Test agent
+    identity: Test identity
+    communication_style: Test style
+    principles:
+      - Test principle
+
+  menu:
+    - trigger: help
+      description: Show help
+      action: "   "

test/fixtures/agent-schema/invalid/menu-commands/no-command-target.agent.yaml

@@ -0,0 +1,23 @@
+# Test: Menu item with no command target fields
+# Expected: FAIL
+# Error code: custom
+# Error path: agent.menu[0]
+# Error message: agent.menu[] entries must include at least one command target field
+
+agent:
+  metadata:
+    id: no-command
+    name: No Command Target
+    title: No Command
+    icon: ❌
+
+  persona:
+    role: Test agent
+    identity: Test identity
+    communication_style: Test style
+    principles:
+      - Test principle
+
+  menu:
+    - trigger: help
+      description: Show help but no command target

test/fixtures/agent-schema/invalid/menu-triggers/camel-case.agent.yaml

@@ -0,0 +1,24 @@
+# Test: CamelCase trigger
+# Expected: FAIL
+# Error code: custom
+# Error path: agent.menu[0].trigger
+# Error message: agent.menu[].trigger must be kebab-case (lowercase words separated by hyphen)
+
+agent:
+  metadata:
+    id: camel-case-trigger
+    name: CamelCase Trigger
+    title: CamelCase
+    icon: ❌
+
+  persona:
+    role: Test agent
+    identity: Test identity
+    communication_style: Test style
+    principles:
+      - Test principle
+
+  menu:
+    - trigger: listTasks
+      description: Invalid CamelCase trigger
+      action: list_tasks

test/fixtures/agent-schema/invalid/menu-triggers/duplicate-triggers.agent.yaml

@@ -0,0 +1,30 @@
+# Test: Duplicate triggers within same agent
+# Expected: FAIL
+# Error code: custom
+# Error path: agent.menu[2].trigger
+# Error message: agent.menu[].trigger duplicates "help" within the same agent
+
+agent:
+  metadata:
+    id: duplicate-triggers
+    name: Duplicate Triggers
+    title: Duplicate
+    icon: ❌
+
+  persona:
+    role: Test agent
+    identity: Test identity
+    communication_style: Test style
+    principles:
+      - Test principle
+
+  menu:
+    - trigger: help
+      description: First help command
+      action: display_help
+    - trigger: list-tasks
+      description: List tasks
+      action: list_tasks
+    - trigger: help
+      description: Duplicate help command
+      action: show_help

test/fixtures/agent-schema/invalid/menu-triggers/empty-trigger.agent.yaml

@@ -0,0 +1,24 @@
+# Test: Empty trigger string
+# Expected: FAIL
+# Error code: custom
+# Error path: agent.menu[0].trigger
+# Error message: agent.menu[].trigger must be a non-empty string
+
+agent:
+  metadata:
+    id: empty-trigger
+    name: Empty Trigger
+    title: Empty
+    icon: ❌
+
+  persona:
+    role: Test agent
+    identity: Test identity
+    communication_style: Test style
+    principles:
+      - Test principle
+
+  menu:
+    - trigger: "   "
+      description: Empty trigger
+      action: display_help

test/fixtures/agent-schema/invalid/menu-triggers/leading-asterisk.agent.yaml

@@ -0,0 +1,24 @@
+# Test: Trigger with leading asterisk
+# Expected: FAIL
+# Error code: custom
+# Error path: agent.menu[0].trigger
+# Error message: agent.menu[].trigger must be kebab-case (lowercase words separated by hyphen)
+
+agent:
+  metadata:
+    id: asterisk-trigger
+    name: Asterisk Trigger
+    title: Asterisk
+    icon: ❌
+
+  persona:
+    role: Test agent
+    identity: Test identity
+    communication_style: Test style
+    principles:
+      - Test principle
+
+  menu:
+    - trigger: "*help"
+      description: Invalid trigger with asterisk
+      action: display_help

test/fixtures/agent-schema/invalid/menu-triggers/snake-case.agent.yaml

@@ -0,0 +1,24 @@
+# Test: Snake_case trigger
+# Expected: FAIL
+# Error code: custom
+# Error path: agent.menu[0].trigger
+# Error message: agent.menu[].trigger must be kebab-case (lowercase words separated by hyphen)
+
+agent:
+  metadata:
+    id: snake-case-trigger
+    name: Snake Case Trigger
+    title: Snake Case
+    icon: ❌
+
+  persona:
+    role: Test agent
+    identity: Test identity
+    communication_style: Test style
+    principles:
+      - Test principle
+
+  menu:
+    - trigger: list_tasks
+      description: Invalid snake_case trigger
+      action: list_tasks

test/fixtures/agent-schema/invalid/menu-triggers/trigger-with-spaces.agent.yaml

@@ -0,0 +1,24 @@
+# Test: Trigger with spaces
+# Expected: FAIL
+# Error code: custom
+# Error path: agent.menu[0].trigger
+# Error message: agent.menu[].trigger must be kebab-case (lowercase words separated by hyphen)
+
+agent:
+  metadata:
+    id: spaces-trigger
+    name: Spaces Trigger
+    title: Spaces
+    icon: ❌
+
+  persona:
+    role: Test agent
+    identity: Test identity
+    communication_style: Test style
+    principles:
+      - Test principle
+
+  menu:
+    - trigger: list tasks
+      description: Invalid trigger with spaces
+      action: list_tasks

test/fixtures/agent-schema/invalid/menu/empty-menu.agent.yaml

@@ -0,0 +1,21 @@
+# Test: Empty menu array
+# Expected: FAIL
+# Error code: too_small
+# Error path: agent.menu
+# Error minimum: 1
+
+agent:
+  metadata:
+    id: empty-menu
+    name: Empty Menu
+    title: Empty Menu
+    icon: ❌
+
+  persona:
+    role: Test agent
+    identity: Test identity
+    communication_style: Test style
+    principles:
+      - Test principle
+
+  menu: []

test/fixtures/agent-schema/invalid/menu/missing-menu.agent.yaml

@@ -0,0 +1,19 @@
+# Test: Missing menu field
+# Expected: FAIL
+# Error code: invalid_type
+# Error path: agent.menu
+# Error expected: array
+
+agent:
+  metadata:
+    id: missing-menu
+    name: Missing Menu
+    title: Missing Menu
+    icon: ❌
+
+  persona:
+    role: Test agent
+    identity: Test identity
+    communication_style: Test style
+    principles:
+      - Test principle

test/fixtures/agent-schema/invalid/metadata/core-agent-with-module.agent.yaml

@@ -0,0 +1,26 @@
+# Test: Core agent with unexpected module field
+# Expected: FAIL
+# Error code: custom
+# Error path: agent.metadata.module
+# Error message: core agents must not include agent.metadata.module
+# Path context: src/core/agents/core-agent-with-module.agent.yaml
+
+agent:
+  metadata:
+    id: core-with-module
+    name: Core With Module
+    title: Core Agent
+    icon: ❌
+    module: bmm
+
+  persona:
+    role: Test agent
+    identity: Test identity
+    communication_style: Test style
+    principles:
+      - Test principle
+
+  menu:
+    - trigger: help
+      description: Show help
+      action: display_help

test/fixtures/agent-schema/invalid/metadata/empty-module-string.agent.yaml

@@ -0,0 +1,26 @@
+# Test: Module field with whitespace only
+# Expected: FAIL
+# Error code: custom
+# Error path: agent.metadata.module
+# Error message: agent.metadata.module must be a non-empty string
+# Path context: src/modules/bmm/agents/empty-module-string.agent.yaml
+
+agent:
+  metadata:
+    id: empty-module
+    name: Empty Module String
+    title: Empty Module
+    icon: ❌
+    module: "   "
+
+  persona:
+    role: Test agent
+    identity: Test identity
+    communication_style: Test style
+    principles:
+      - Test principle
+
+  menu:
+    - trigger: help
+      description: Show help
+      action: display_help

test/fixtures/agent-schema/invalid/metadata/empty-name.agent.yaml

@@ -0,0 +1,24 @@
+# Test: Empty string in metadata.name field
+# Expected: FAIL
+# Error code: custom
+# Error path: agent.metadata.name
+# Error message: agent.metadata.name must be a non-empty string
+
+agent:
+  metadata:
+    id: empty-name-test
+    name: "   "
+    title: Empty Name Test
+    icon: ❌
+
+  persona:
+    role: Test agent
+    identity: Test identity
+    communication_style: Test style
+    principles:
+      - Test principle
+
+  menu:
+    - trigger: help
+      description: Show help
+      action: display_help

test/fixtures/agent-schema/invalid/metadata/extra-metadata-fields.agent.yaml

@@ -0,0 +1,26 @@
+# Test: Extra unknown fields in metadata
+# Expected: FAIL
+# Error code: unrecognized_keys
+# Error path: agent.metadata
+# Error keys: ["unknown_field", "another_extra"]
+
+agent:
+  metadata:
+    id: extra-fields
+    name: Extra Fields
+    title: Extra Fields
+    icon: ❌
+    unknown_field: This is not allowed
+    another_extra: Also invalid
+
+  persona:
+    role: Test agent
+    identity: Test identity
+    communication_style: Test style
+    principles:
+      - Test principle
+
+  menu:
+    - trigger: help
+      description: Show help
+      action: display_help

test/fixtures/agent-schema/invalid/metadata/missing-id.agent.yaml

@@ -0,0 +1,23 @@
+# Test: Missing required metadata.id field
+# Expected: FAIL
+# Error code: invalid_type
+# Error path: agent.metadata.id
+# Error expected: string
+
+agent:
+  metadata:
+    name: Missing ID Agent
+    title: Missing ID
+    icon: ❌
+
+  persona:
+    role: Test agent
+    identity: Test identity
+    communication_style: Test style
+    principles:
+      - Test principle
+
+  menu:
+    - trigger: help
+      description: Show help
+      action: display_help

test/fixtures/agent-schema/invalid/metadata/module-agent-missing-module.agent.yaml

@@ -0,0 +1,25 @@
+# Test: Module agent missing required module field
+# Expected: FAIL
+# Error code: custom
+# Error path: agent.metadata.module
+# Error message: module-scoped agents must declare agent.metadata.module
+# Path context: src/modules/bmm/agents/module-agent-missing-module.agent.yaml
+
+agent:
+  metadata:
+    id: bmm-missing-module
+    name: BMM Missing Module
+    title: Missing Module
+    icon: ❌
+
+  persona:
+    role: Test agent
+    identity: Test identity
+    communication_style: Test style
+    principles:
+      - Test principle
+
+  menu:
+    - trigger: help
+      description: Show help
+      action: display_help

test/fixtures/agent-schema/invalid/metadata/wrong-module-value.agent.yaml

@@ -0,0 +1,26 @@
+# Test: Module agent with wrong module value
+# Expected: FAIL
+# Error code: custom
+# Error path: agent.metadata.module
+# Error message: agent.metadata.module must equal "bmm"
+# Path context: src/modules/bmm/agents/wrong-module-value.agent.yaml
+
+agent:
+  metadata:
+    id: wrong-module
+    name: Wrong Module
+    title: Wrong Module
+    icon: ❌
+    module: cis
+
+  persona:
+    role: Test agent
+    identity: Test identity
+    communication_style: Test style
+    principles:
+      - Test principle
+
+  menu:
+    - trigger: help
+      description: Show help
+      action: display_help

test/fixtures/agent-schema/invalid/persona/empty-principles-array.agent.yaml

@@ -0,0 +1,23 @@
+# Test: Empty principles array
+# Expected: FAIL
+# Error code: too_small
+# Error path: agent.persona.principles
+# Error minimum: 1
+
+agent:
+  metadata:
+    id: empty-principles
+    name: Empty Principles
+    title: Empty Principles
+    icon: ❌
+
+  persona:
+    role: Test agent
+    identity: Test identity
+    communication_style: Test style
+    principles: []
+
+  menu:
+    - trigger: help
+      description: Show help
+      action: display_help

test/fixtures/agent-schema/invalid/persona/empty-string-in-principles.agent.yaml

@@ -0,0 +1,26 @@
+# Test: Empty string in principles array
+# Expected: FAIL
+# Error code: custom
+# Error path: agent.persona.principles[1]
+# Error message: agent.persona.principles[] must be a non-empty string
+
+agent:
+  metadata:
+    id: empty-principle-string
+    name: Empty Principle String
+    title: Empty Principle
+    icon: ❌
+
+  persona:
+    role: Test agent
+    identity: Test identity
+    communication_style: Test style
+    principles:
+      - Valid principle
+      - "   "
+      - Another valid principle
+
+  menu:
+    - trigger: help
+      description: Show help
+      action: display_help

test/fixtures/agent-schema/invalid/persona/extra-persona-fields.agent.yaml

@@ -0,0 +1,26 @@
+# Test: Extra unknown fields in persona
+# Expected: FAIL
+# Error code: unrecognized_keys
+# Error path: agent.persona
+# Error keys: ["extra_field", "another_extra"]
+
+agent:
+  metadata:
+    id: extra-persona-fields
+    name: Extra Persona Fields
+    title: Extra Persona
+    icon: ❌
+
+  persona:
+    role: Test agent
+    identity: Test identity
+    communication_style: Test style
+    principles:
+      - Test principle
+    extra_field: Not allowed
+    another_extra: Also invalid
+
+  menu:
+    - trigger: help
+      description: Show help
+      action: display_help

test/fixtures/agent-schema/invalid/persona/missing-role.agent.yaml

@@ -0,0 +1,23 @@
+# Test: Missing required persona.role field
+# Expected: FAIL
+# Error code: invalid_type
+# Error path: agent.persona.role
+# Error expected: string
+
+agent:
+  metadata:
+    id: missing-role
+    name: Missing Role
+    title: Missing Role
+    icon: ❌
+
+  persona:
+    identity: Test identity
+    communication_style: Test style
+    principles:
+      - Test principle
+
+  menu:
+    - trigger: help
+      description: Show help
+      action: display_help

test/fixtures/agent-schema/invalid/persona/principles-as-string.agent.yaml

@@ -0,0 +1,23 @@
+# Test: principles as string instead of array
+# Expected: FAIL
+# Error code: invalid_type
+# Error path: agent.persona.principles
+# Error expected: array
+
+agent:
+  metadata:
+    id: principles-string
+    name: Principles String
+    title: Principles String
+    icon: ❌
+
+  persona:
+    role: Test agent
+    identity: Test identity
+    communication_style: Test style
+    principles: This should be an array, not a string
+
+  menu:
+    - trigger: help
+      description: Show help
+      action: display_help

test/fixtures/agent-schema/invalid/prompts/empty-content.agent.yaml

@@ -0,0 +1,28 @@
+# Test: Prompt with empty content string
+# Expected: FAIL
+# Error code: custom
+# Error path: agent.prompts[0].content
+# Error message: agent.prompts[].content must be a non-empty string
+
+agent:
+  metadata:
+    id: empty-content
+    name: Empty Content
+    title: Empty Content
+    icon: ❌
+
+  persona:
+    role: Test agent
+    identity: Test identity
+    communication_style: Test style
+    principles:
+      - Test principle
+
+  prompts:
+    - id: prompt1
+      content: "   "
+
+  menu:
+    - trigger: help
+      description: Show help
+      action: display_help

test/fixtures/agent-schema/invalid/prompts/extra-prompt-fields.agent.yaml

@@ -0,0 +1,30 @@
+# Test: Extra unknown fields in prompts
+# Expected: FAIL
+# Error code: unrecognized_keys
+# Error path: agent.prompts[0]
+# Error keys: ["extra_field"]
+
+agent:
+  metadata:
+    id: extra-prompt-fields
+    name: Extra Prompt Fields
+    title: Extra Fields
+    icon: ❌
+
+  persona:
+    role: Test agent
+    identity: Test identity
+    communication_style: Test style
+    principles:
+      - Test principle
+
+  prompts:
+    - id: prompt1
+      content: Valid content
+      description: Valid description
+      extra_field: Not allowed
+
+  menu:
+    - trigger: help
+      description: Show help
+      action: display_help

test/fixtures/agent-schema/invalid/prompts/missing-content.agent.yaml

@@ -0,0 +1,27 @@
+# Test: Prompt missing required content field
+# Expected: FAIL
+# Error code: invalid_type
+# Error path: agent.prompts[0].content
+# Error expected: string
+
+agent:
+  metadata:
+    id: prompt-missing-content
+    name: Prompt Missing Content
+    title: Missing Content
+    icon: ❌
+
+  persona:
+    role: Test agent
+    identity: Test identity
+    communication_style: Test style
+    principles:
+      - Test principle
+
+  prompts:
+    - id: prompt1
+
+  menu:
+    - trigger: help
+      description: Show help
+      action: display_help

test/fixtures/agent-schema/invalid/prompts/missing-id.agent.yaml

@@ -0,0 +1,27 @@
+# Test: Prompt missing required id field
+# Expected: FAIL
+# Error code: invalid_type
+# Error path: agent.prompts[0].id
+# Error expected: string
+
+agent:
+  metadata:
+    id: prompt-missing-id
+    name: Prompt Missing ID
+    title: Missing ID
+    icon: ❌
+
+  persona:
+    role: Test agent
+    identity: Test identity
+    communication_style: Test style
+    principles:
+      - Test principle
+
+  prompts:
+    - content: Prompt without ID
+
+  menu:
+    - trigger: help
+      description: Show help
+      action: display_help

test/fixtures/agent-schema/invalid/top-level/empty-file.agent.yaml

@@ -0,0 +1,5 @@
+# Test: Empty YAML file
+# Expected: FAIL
+# Error code: invalid_type
+# Error path:
+# Error expected: object

test/fixtures/agent-schema/invalid/top-level/extra-top-level-keys.agent.yaml

@@ -0,0 +1,27 @@
+# Test: Extra top-level keys beyond 'agent'
+# Expected: FAIL
+# Error code: unrecognized_keys
+# Error path: 
+# Error keys: ["extra_key", "another_extra"]
+
+agent:
+  metadata:
+    id: extra-test
+    name: Extra Test Agent
+    title: Extra Test
+    icon: 🧪
+
+  persona:
+    role: Test agent
+    identity: Test identity
+    communication_style: Test style
+    principles:
+      - Test principle
+
+  menu:
+    - trigger: help
+      description: Show help
+      action: display_help
+
+extra_key: This should not be allowed
+another_extra: Also invalid

test/fixtures/agent-schema/invalid/top-level/missing-agent-key.agent.yaml

@@ -0,0 +1,11 @@
+# Test: Missing required 'agent' top-level key
+# Expected: FAIL
+# Error code: invalid_type
+# Error path: agent
+# Error expected: object
+
+metadata:
+  id: bad-test
+  name: Bad Test Agent
+  title: Bad Test
+  icon: ❌

test/fixtures/agent-schema/invalid/yaml-errors/invalid-indentation.agent.yaml

@@ -0,0 +1,19 @@
+# Test: Invalid YAML structure with inconsistent indentation
+# Expected: FAIL - YAML parse error
+
+agent:
+  metadata:
+  id: invalid-indent
+    name: Invalid Indentation
+    title: Invalid
+    icon: ❌
+  persona:
+    role: Test
+    identity: Test
+    communication_style: Test
+    principles:
+      - Test
+  menu:
+    - trigger: help
+      description: Help
+      action: help

test/fixtures/agent-schema/invalid/yaml-errors/malformed-yaml.agent.yaml

@@ -0,0 +1,18 @@
+# Test: Malformed YAML with syntax errors
+# Expected: FAIL - YAML parse error
+
+agent:
+  metadata:
+    id: malformed
+    name: Malformed YAML
+    title: [Malformed
+    icon: 🧪
+  persona:
+    role: Test
+    identity: Test
+    communication_style: Test
+    principles:
+      - Test
+  menu:
+    - trigger: help
+      description: Help