v7.30.20

Packaged product knowledge hotfix. Packaged installs now copy src/product_knowledge into the installed runtime so product knowledge tools import correctly after nexo update. Runtime copy, backup, shim and installer paths now preserve product_knowledge, with smoke evidence in release-contracts/smoke/v7.30.20.json. Supersedes v7.30.19 for packaged installs.\n\nValidation: pre-release-verify passed (3114 passed, 2 skipped, 1 xfailed, 4 xpassed); verify_release_readiness --require-smoke passed with 6 smoke groups.\n\nFull Changelog: v7.30.19...v7.30.20

Full Changelog: v7.30.19...v7.30.20