Rework public docs and first-run experience around simulator plus design platform

[DennisWayo]

Problem Statement

The README and docs already mention design, compilation, simulation, validation, and Studio. The Gottesman Software site positions the larger program around photonic circuit design, decoder validation, and lab-facing prototype evidence. SchroSIM should make that product direction obvious: it is not only a simulator, it is a design platform for photonic quantum circuit studies.

Proposed Solution

Update the public narrative and docs structure:

• README language: "simulator plus design platform" with clear boundaries,
• docs landing page split into Design, Compile, Simulate, Validate, Replay,
• Studio quickstart with a design-first example,
• docs page for evidence bundles and foundry-aware workflows,
• screenshots/GIFs generated from current Studio behavior,
• comparison section updated to emphasize design workflow, not only backend execution.

Acceptance Criteria

• docs/index.md, README.md, and docs/14-schrosim-studio.md tell the same story.
• New users can complete a design-to-result walkthrough without reading source code.
• Claims distinguish implemented behavior from roadmap items.
• mkdocs build --strict passes.
• Gottesman site links and SchroSIM docs do not contradict each other.

Validation

mkdocs build --strict

Evidence

• README.md
• docs/index.md
• docs/14-schrosim-studio.md
• studio/docs/SWIFTUI_STUDIO_UI_ARCHITECTURE.md
• https://gottesman-software.github.io/