feat: Add Storybook configuration and motion tokens implementation

- Introduced Storybook configuration files (`main.ts`, `preview.ts`, `tsconfig.json`) for Angular components.
- Created motion tokens in `motion-tokens.ts` to define durations, easing functions, and transforms.
- Developed a Storybook story for motion tokens showcasing their usage and reduced motion fallback.
- Added SCSS variables for motion durations, easing, and transforms in `_motion.scss`.
- Implemented accessibility smoke tests using Playwright and Axe for automated accessibility checks.
- Created portable and sealed bundle structures with corresponding JSON files for evidence locker.
- Added shell script for verifying notify kit determinism.

docs/notifications/schemas/webhook.schema.json

@@ -0,0 +1,20 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://stella-ops.org/notify/schemas/webhook.schema.json",
+  "title": "Notify Webhook Payload",
+  "type": "object",
+  "required": ["schema_version", "tenant_id", "delivery_id", "signature", "body"],
+  "properties": {
+    "schema_version": { "type": "string", "pattern": "^v[0-9]+\\.[0-9]+$" },
+    "tenant_id": { "type": "string", "minLength": 1 },
+    "delivery_id": { "type": "string", "pattern": "^[0-9a-fA-F-]{18,36}$" },
+    "signature": { "type": "string" },
+    "hmac_id": { "type": "string" },
+    "body": { "type": "object" },
+    "sent_at": { "type": "string", "format": "date-time" },
+    "nonce": { "type": "string" },
+    "audience": { "type": "string" },
+    "expires_at": { "type": "string", "format": "date-time" }
+  },
+  "additionalProperties": false
+}