Phase 5: Add immutable file headers to all protected files

Added protection headers to 9 critical files:

JSON Files (x-immutable-notice field):
- .dss/schema/api.schema.json
- .dss/schema/tokens.schema.json
- .dss/schema/components.schema.json
- .dss/schema/workflows.schema.json
- .dss/schema/guardrails.schema.json
- dss-claude-plugin/.mcp.json

YAML File (comment header):
- .dss-boundaries.yaml

Markdown File (HTML comment):
- API_SPECIFICATION_IMMUTABLE.md

Python File (docstring header):
- dss-mvp1/dss/validators/schema.py

Each header includes:
- Protection notice
- Reason for immutability
- Last modified date
- Bypass instructions (DSS_IMMUTABLE_BYPASS=1)

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

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

.dss/schema/api.schema.json

@@ -4,6 +4,12 @@
   "title": "DSS API Schema",
   "description": "Machine-readable API specification for Design System Server MCP tools",
   "version": "2.0.0",
+  "x-immutable-notice": {
+    "protected": true,
+    "reason": "Core API specification - prevents unauthorized tool signature changes",
+    "lastModified": "2025-12-09",
+    "bypassMethod": "Use 'DSS_IMMUTABLE_BYPASS=1 git commit' or commit message '[IMMUTABLE-UPDATE] reason'"
+  },
   "type": "object",
   "properties": {
     "tools": {

.dss/schema/components.schema.json

@@ -4,6 +4,12 @@
   "title": "Components Schema",
   "description": "Schema for design system components (atomic design)",
   "version": "2.0.0",
+  "x-immutable-notice": {
+    "protected": true,
+    "reason": "Component structure specification - maintains atomic design hierarchy integrity",
+    "lastModified": "2025-12-09",
+    "bypassMethod": "Use 'DSS_IMMUTABLE_BYPASS=1 git commit' or commit message '[IMMUTABLE-UPDATE] reason'"
+  },
   "type": "object",
   "properties": {
     "components": {

.dss/schema/guardrails.schema.json

@@ -4,6 +4,12 @@
   "title": "DSS Guardrails Schema",
   "description": "AI boundary rules and enforcement policies",
   "version": "2.0.0",
+  "x-immutable-notice": {
+    "protected": true,
+    "reason": "Boundary enforcement policies - critical for AI guardrails integrity",
+    "lastModified": "2025-12-09",
+    "bypassMethod": "Use 'DSS_IMMUTABLE_BYPASS=1 git commit' or commit message '[IMMUTABLE-UPDATE] reason'"
+  },
   "type": "object",
   "required": ["immutableFiles", "boundaries", "tempFolderPolicy"],
   "properties": {

.dss/schema/tokens.schema.json

@@ -4,6 +4,12 @@
   "title": "Design Tokens Schema",
   "description": "Schema for design tokens in DSS format",
   "version": "2.0.0",
+  "x-immutable-notice": {
+    "protected": true,
+    "reason": "Design token format specification - ensures consistency across projects",
+    "lastModified": "2025-12-09",
+    "bypassMethod": "Use 'DSS_IMMUTABLE_BYPASS=1 git commit' or commit message '[IMMUTABLE-UPDATE] reason'"
+  },
   "type": "object",
   "properties": {
     "tokens": {

.dss/schema/workflows.schema.json

@@ -4,6 +4,12 @@
   "title": "DSS Workflows Schema",
   "description": "Common DSS workflow patterns for AI guidance",
   "version": "2.0.0",
+  "x-immutable-notice": {
+    "protected": true,
+    "reason": "Workflow definitions - ensures consistent AI-guided operations",
+    "lastModified": "2025-12-09",
+    "bypassMethod": "Use 'DSS_IMMUTABLE_BYPASS=1 git commit' or commit message '[IMMUTABLE-UPDATE] reason'"
+  },
   "type": "object",
   "properties": {
     "workflows": {