Run Configuration: populate parameters & secrets from the build's declarations

**Problem**

The extension's Run Configuration view is free-form — it only shows params/secrets you hand-type. Declared members like `NuGetApiKey` (`[Parameter][Secret]`) don't appear, so the Secrets section looks empty.

Blocked on **Fallout-build/Fallout#499** (the framework graph must emit `parameters[]` first).

**Outcome**

Run Configuration reads `parameters[]` from `build-graph.json` and pre-populates:
- non-secret params → **Parameters** rows (fill value → CLI args)
- `[Secret]` params → **Secrets** rows, shown *"not set"* until a value is entered (→ SecretStorage → env var on run)

**Acceptance criteria**

- `NuGetApiKey` and peers appear automatically after a build/plan.
- Declared secrets read *"not set"* until set; values live in SecretStorage, applied as env vars on run.
- Values still flow to runs as today (params → args, secrets → env); free-form add still works for extras.
- Graceful when the graph has no `parameters[]` (older builds) — falls back to today's free-form behaviour.