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/event-envelope.schema.json

@@ -0,0 +1,26 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://stella-ops.org/notify/schemas/event-envelope.schema.json",
+  "title": "Notify Event Envelope",
+  "type": "object",
+  "required": [
+    "schema_version",
+    "tenant_id",
+    "event_id",
+    "occurred_at",
+    "kind",
+    "payload"
+  ],
+  "properties": {
+    "schema_version": { "type": "string", "pattern": "^v[0-9]+\\.[0-9]+$" },
+    "tenant_id": { "type": "string", "minLength": 1 },
+    "event_id": { "type": "string", "pattern": "^[0-9a-fA-F-]{18,36}$" },
+    "occurred_at": { "type": "string", "format": "date-time" },
+    "kind": { "type": "string", "minLength": 1 },
+    "correlation_id": { "type": "string" },
+    "source": { "type": "string" },
+    "payload": { "type": "object" },
+    "attributes": { "type": "object", "additionalProperties": { "type": ["string", "number", "boolean", "null"] } }
+  },
+  "additionalProperties": false
+}