feat: add content type intake policy support

[ebarroca]

Summary

• Add shared content type intake policy fields and JSON schema for type-driven text conversion, extraction, rendering, and embedding behavior.
• Update workflow activities to use explicit text, vision, mixed, and auto extraction sources with fallback type assignment behavior.
• Add schema-backed intake policy editor UI exports for content type configuration.
• Fix the template smoke Verdaccio config so public scoped transitive packages proxy to npm while Vertesia/Llumiverse scopes stay local.

Test Plan

• ../../node_modules/.bin/tsc -p tsconfig.json --noEmit (packages/common)
• ../../node_modules/.bin/tsc -p tsconfig.json --noEmit (packages/ui)
• ../../node_modules/.bin/tsc -p tsconfig.json --noEmit (packages/client)
• ../../node_modules/.bin/tsc -p tsconfig.test.json --noEmit (packages/workflow)
• ./node_modules/.bin/vitest run src/activities/generateDocumentProperties.test.ts src/activities/generateOrAssignContentType.test.ts (packages/workflow)
• ./.github/bin/test-template-integration.sh --release-type snapshot --template "Vertesia Plugin"
• CI for a72a862: Check codebase, Unit tests, Template smoke test (Plugin), CodeQL, and zizmor passed.