feat(lab12): add wasm time endpoint

[BearAx]

Goal

Build Lab 12 WebAssembly deployment artifacts for QuickNotes-style time service, compare Spin against Docker, and complete the Wasmtime bonus.

Changes

• Added wasm/moscow-time Spin http-go component serving /time.
• Added committed Spin main.wasm artifact and pinned Go SDK dependencies.
• Added standalone wasm-cli WASI module for bare wasmtime run.
• Added Lab 6-style Docker baseline for comparison.
• Added Spin, Docker, and Wasmtime benchmark evidence under security/lab12.
• Updated submissions/lab12.md with design answers, measurements, and bonus results.

Testing

• Verified course upstream main at 8de962e
• go test ./...
• spin build
• Spin /time smoke test
• tinygo build -o main.wasm -target=wasi -no-debug ./main.go
• wasmtime run --env REQUEST_METHOD=GET --env PATH_INFO=/time wasm-cli/main.wasm
• docker build -f security/lab12/lab6-baseline.Dockerfile -t qn-lab12-docker:verify app
• Docker /health smoke test
• Parsed all Lab 12 JSON evidence files

Evidence

• Spin WASM size: 369,708 bytes
• Wasmtime CLI WASM size: 196,189 bytes
• Docker image size: 2,506,341 bytes
• Spin warm p50/p95: 23.14 ms / 32.08 ms
• Docker warm p50/p95: 23.24 ms / 29.01 ms
• Spin cold p50/p95: 522.5 ms / 646.4 ms
• Docker cold p50/p95: 515.4 ms / 550.1 ms

Checklist

• wasm/ Spin component added
• wasm-cli/ bonus module added
• Benchmark evidence committed
• submissions/lab12.md updated
• Bonus task completed
• Commit is signed