Align docs with flat graph API

[melonamin]

What changed

• update Rust, TypeScript, WASM, root, and quickstart examples to the flat top-level graph API
• replace removed request fields and per-statement node/edge access with current request fields and statement helpers
• compile Rust README examples as crate doctests
• add a TypeScript documentation contract that rejects the stale shapes during package typechecking

Why

Several first-party examples still used removed AnalyzeRequest fields and treated StatementMeta as if it owned graph collections. The runtime API has a flat result.nodes and result.edges graph.

Validation

• cargo test -p flowscope-core --doc --locked
• mise exec yarn@1.22.19 -- yarn workspace @pondpilot/flowscope-core typecheck
• mise exec yarn@1.22.19 -- just check
• Codex review: no actionable findings

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.

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