feat: Add descriptions and deprecations to SDK

[razor-x]

Motivation

• Surface blueprint descriptions and deprecation metadata in the generated TypeScript so IDE hovers and docs include human-readable API documentation.
• Provide a safe formatter for blueprint documentation that can be emitted from Handlebars templates without breaking generated comment blocks.
• Ensure generated route and resource types contain TSDoc comments for parameters, properties, enum values, and endpoint methods to improve developer experience.

Description

• Add a safe TSDoc formatter doc to the codegen helpers at codegen/lib/handlebars-helpers.ts that escapes */, emits @deprecated when appropriate, and returns a TSDoc comment block. (doc, escapeComment)
• Extend the route layout context to carry endpoint documentation metadata (description, isDeprecated, deprecationMessage) in codegen/lib/layouts/route.ts and use it when rendering endpoints.
• Update multiple Handlebars templates to emit documentation for generated artifacts: endpoint methods, request parameters, resource types, resource properties, list/enum items, and enum values (templates under codegen/layouts/partials/* and codegen/layouts/*).
• Regenerate Seam Connect sources so the generated TypeScript under src/lib/seam/connect/* now includes the new TSDoc comments for resource types, routes, request/response types, and many route implementations.

Testing

• Ran npm_config_force=true npm run generate to run the codegen and regenerate sources (used --force due to dev engine constraints), and the generation completed successfully.
• Ran npm_config_force=true npm run typecheck (tsc) and the TypeScript type check completed successfully under the forced install.
• Built documentation with npm_config_force=true npm run docs:build; Typedoc completed and produced ./docs with pre-existing warnings about some cross-references (non-fatal).
• Attempted npm_config_force=true npm test; automated tests could not fully run in this environment because the installed Emittery relies on iterator helpers not present in the runtime Node 20 used here (project requires Node >= 22.11), so tests did not complete in this environment; git diff --check produced no whitespace/comment issues.

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Codex Task