feat(integrations): add railway Stripe catalog provider

[snowmead]

Summary

• Adds the railway Stripe Projects catalog integration family as CatalogResource adapter(s).
• Follows docs/ADDING-A-PROVIDER.md and docs/PROVIDER-WAVES.md.
• Includes gap test + hermetic provision test. OUTPUT_FIELDS provisional until mise run discover.

Test plan

• Gap + hermetic tests in module
• Live mise run discover when provider is linked
• Merge after resolving additive registry.rs conflict with other family PRs

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Note

Low Risk
Additive catalog adapters and tests only; no auth or lifecycle engine changes. Provisional output envelopes may need discover before first live provision.

Overview
Adds Phase 1 Stripe Projects CatalogResource integrations for the full Railway family: railway/bucket, railway/hosting, railway/mongo, railway/postgres, and railway/redis. Each module wires catalog refs, optional config fields, provisional OUTPUT_FIELDS, gap tests against catalog.json, and hermetic provision_script tests; register_providers! and providers/mod.rs register all five, with output-drift assertions extended to Railway types.

SDK: stackless-provider-sdk gains int_optional, bool_required, and bool_optional config helpers (for generated/catalog schemas).

Docs & tooling: PROVIDER-WAVES.md documents parallel wave landing; DECISIONS.md and ADDING-A-PROVIDER.md link catalog-first vs Phase 2 substrates. scripts/generate_catalog_integrations.py is a new generator for remaining deployables (Railway hints included).

Note: OUTPUT_FIELDS stay provisional until live mise run discover; this PR does not add --on railway or smoke fixtures.

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Cursor Bugbot has reviewed your changes using default effort and found 1 potential issue.

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Generator omits implemented Railway refs

Medium Severity

The new codegen script lists railway/* hints and maps but leaves all five Railway deployables out of IMPLEMENTED. Running the generator still treats them as missing and can rewrite providers/railway/ and rebuild registry rows over the hand-landed adapters.

 

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