feat: Add HTTP status tests and dynamic plugin documentation

- Add e2e_vm_http_status_404/500 tests to verify HTTP status handling
- ResultBox properly returns Ok(Response) for HTTP errors, Err for connection failures
- Create dynamic-plugin-flow.md documenting MIR→VM→Registry→Plugin flow
- Add vm-stats test files for HTTP 404/500 status codes
- Update net-plugin.md with HTTP error handling clarification
- Create E2E_TESTS.md documenting all E2E test behaviors
- Add mir-26-instruction-diet.md for MIR optimization plans
- Add vm-stats-cookbook.md for VM statistics usage guide
- Update MIR verifier to properly track self-assignment patterns

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

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

.github/workflows/plugins-e2e.yml

@@ -0,0 +1,41 @@
+name: Plugins E2E (Linux)
+
+on:
+  push:
+    branches: [ main, dev ]
+  pull_request:
+    branches: [ main, dev ]
+
+jobs:
+  plugins-e2e:
+    runs-on: ubuntu-latest
+    timeout-minutes: 15
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Setup Rust
+        uses: actions-rs/toolchain@v1
+        with:
+          toolchain: stable
+          override: true
+
+      - name: Cache cargo
+        uses: actions/cache@v4
+        with:
+          path: |
+            ~/.cargo/registry
+            ~/.cargo/git
+            target
+          key: ${{ runner.os }}-cargo-${{ hashFiles('**/Cargo.lock') }}
+
+      - name: Build (release)
+        run: cargo build --release -j2
+
+      - name: Run E2E with plugins (Linux)
+        env:
+          RUST_BACKTRACE: 1
+          NYASH_NET_LOG: "0"
+        run: |
+          cargo test --features plugins -q -- --nocapture
+