[Docs] Visualize supported scenarios and their verification evidence

[szmyty]

Outcome

Make flow's supported and tested scenarios easy to understand and showcase in the documentation. A reader should be able to browse a visual catalog, see what each scenario demonstrates, and follow its verification evidence without reading the test implementation.

Suite roadmap: #11
Builds on: #30 / PR #61 and the scenario contract in #28
Coordinates with: #13 and #34 (scenario coverage and reporting)
Scheduling: later documentation work; does not block #49, #31, or the existing implementation sequence.

Starting point

PR #61 introduces 81 acceptance scenarios covering resolution, contracts, artifacts, provider failures, and privacy. Use its merged versions of:

• tests/fixtures/acceptance-scenarios.v1.json — stable scenario IDs, expected outcomes, budgets, and known gaps.
• tools/run_acceptance_scenarios.py and its versioned normalized report — actual verification evidence and tested source identity.
• docs/integrations/acceptance-scenarios.md — interpretation and claim limits.

Re-query the catalog and merged state when implementation begins; 81 is the initial snapshot, not a permanent hard-coded count.

Proposed scope

• Add an overview matrix or gallery grouped by scenario family, with plain-language titles and explanations of why each case matters.
• Give scenarios stable links and show the setup or injected fault, expected flow response, acceptance/refusal outcome, and relevant contract or evidence.
• Include a few representative diagrams showing provider execution, validation decisions, and resulting outcomes. Choose the simplest presentation supported by the existing documentation stack; searchable/filterable views are optional.
• Distinguish a test passing from a provider result being accepted: a correctly rejected invalid result is a passing test. Preserve complete, observed-empty, unavailable, incomplete, unsupported, invalid, and failed evidence states.
• Clearly identify synthetic contract coverage, verified real-provider coverage, and planned or unproven capabilities. Resolution or transcript validation alone must not be presented as accepted execution.
• Generate or validate IDs, counts, expected outcomes, and coverage from canonical data. Explanatory copy should be keyed by scenario ID rather than becoming a second hand-maintained coverage inventory.
• Link observed verification to its tested revision and report identity. Missing, expired, stale, or mismatched evidence must not appear as currently verified. Use only portable normalized evidence.
• Link the showcase from the README/integration documentation and leave room for later [FLO-13.4] Prove interruption, retry, resume, and authority state transitions #31–[FLO-13.7] Add clean-room compatibility, CI tiers, and regression promotion #34 scenario families without claiming their support early.

Acceptance criteria

• Readers can browse all current catalog scenarios and understand representative success and refusal cases without opening Rust source.
• Every displayed scenario maps to a stable canonical ID; IDs, counts, and expected outcomes stay synchronized through generation or a drift check.
• The presentation distinguishes expected behavior, observed verification, and known coverage gaps.
• Evidence links identify what revision was tested; unavailable or stale evidence is clearly labeled.
• Diagrams have readable text equivalents; status does not rely on color alone.
• The showcase builds locally using the existing docs tooling, with documented refresh instructions and no new paid CI dependency.

Boundaries

This issue owns documentation presentation. #34 continues to own coverage-reporting and release-gate semantics. It does not add runtime capabilities, a hosted dashboard, or new provider support.