chore: checkpoint web Blender feature-gap work, docs and tests

- update native web_engine sources and rebuilt wasm artifacts
- add task cards, status notes and tooling scripts
- add web e2e specs, tutorial UI sources and tutorial assets
- sync golden task manifests and audit records

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

test-results/.last-run.json

@@ -1,6 +1,4 @@
 {
   "status": "failed",
-  "failedTests": [
-    "44d526552dd243783a40-2cb37a5217f2f6418146"
-  ]
+  "failedTests": []
 }

test-results/web-tests-e2e-script-signa-c7cc3-lidates-source-hash-changes/error-context.md

@@ -1,24 +0,0 @@
-# Instructions
-
-- Following Playwright test failed.
-- Explain why, be concise, respect Playwright best practices.
-- Provide a snippet of code with the fix, if possible.
-
-# Test info
-
-- Name: web/tests/e2e/script-signature.spec.ts >> M13-02D verifies declared script content and invalidates source hash changes
-- Location: web/tests/e2e/script-signature.spec.ts:3:1
-
-# Error details
-
-```
-Error: browserType.launch: Executable doesn't exist at /home/mes123456/.cache/ms-playwright/chromium_headless_shell-1234/chrome-headless-shell-linux64/chrome-headless-shell
-╔════════════════════════════════════════════════════════════╗
-║ Looks like Playwright was just installed or updated.       ║
-║ Please run the following command to download new browsers: ║
-║                                                            ║
-║     npx playwright install                                 ║
-║                                                            ║
-║ <3 Playwright Team                                         ║
-╚════════════════════════════════════════════════════════════╝
-```