feat(integrations): add postalform Stripe catalog provider

[snowmead]

Summary

• Adds the postalform 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 provider registration and offline tests; provisional output envelope is documented and unchanged from other catalog adapters until discover.

Overview
Adds a PostalForm Phase 1 Stripe Projects catalog integration for postalform/mail: managed CatalogResource with optional webhook_url / workspace_name, provisional api_key output until mise run discover, plus catalog gap and hermetic provision tests. Wires it through register_providers!, providers/mod.rs, and an assert_outputs_match row for PostalFormMail.

Also extends stackless-provider-sdk with shared int_optional, bool_required, and bool_optional config helpers (for generated catalog modules), documents catalog-first waves in PROVIDER-WAVES.md, DECISIONS.md, and ADDING-A-PROVIDER.md, and adds scripts/generate_catalog_integrations.py to scaffold remaining deployables.

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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 registry rows

High Severity

The catalog generator rebuilds register_providers! and providers/mod.rs from only hardcoded Clerk/Cloudflare rows plus services it generates this run. It never keeps families already landed manually, and postalform/mail is missing from IMPLEMENTED. After postalform/mail is added to IMPLEMENTED, a normal generator run drops postalform from the registry and pub mod list while the on-disk module remains, so provider = "postalform" stops resolving.

Additional Locations (2)

• scripts/generate_catalog_integrations.py#L660-L706
• scripts/generate_catalog_integrations.py#L16-L32

 

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