proto: publish common v1 contracts

[haasonsaas]

Summary

• publishes the shared common/v1 proto package and generated Go/TS/Python/OpenAPI artifacts
• unblocks platform agent-mcp mirror builds that import commonv1 transitively through public proto packages

Test plan

• make generate
• make lint
• go test ./...
• git diff --check

[cursor]

PR Summary

Low Risk
Mostly additive proto/API surface and generated artifacts; primary risk is downstream compatibility/packaging issues if consumers assume different common.v1 definitions or export paths.

Overview
Publishes a new shared common/v1 proto package (analytics time/money/evidence types, DeliveryChannel, EntityType, and RiskLevel) plus authz method-option extensions for required_scopes, workspace_scope_field, risk_level, and public.

Adds generated artifacts for Go, Python, TypeScript, and OpenAPI, and updates package.json exports so TS consumers can import the new common/v1/*_pb modules.

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