What

Four page-world (world: "MAIN") features — webdriver-probe,
checkout-checkbox-defense, shadow-root-probe, and dump-trace-bridge —
each shipped the same four-part shape: a *-registration.ts with an ~80 LOC
register/isRegistered/unregister/sync/start lifecycle keyed on a
toggle, a *-source.ts page-world install fn, a thin entry file, and (for
three of them) a byte-identical executeScript({ world: "MAIN", func })
inject-* handler in background.ts.

This collapses the duplicated lifecycle and dispatch into:

• lib/page-world-hook.ts — createPageWorldHook({ scriptId, scriptFile, logLabel, allFrames, shouldRegister, subscribe }) owns the register/sync
  reconcile once, plus injectPageWorldScript(sender, installFn, messageType)
  for the on-demand fallback.
• lib/page-world-hooks.ts — the four hooks as four config objects in one
  table, startPageWorldHooks(), and a table-driven
  dispatchPageWorldInject().
• background.ts — the three inject-* if blocks become one dispatch
  call; the four start*Registration() calls become startPageWorldHooks().

Why

Drift had already started: the dump-trace variant used a different
shouldRegister predicate and allFrames value, so the "same" pattern was
silently divergent. Adding a fifth page-world hook meant touching 4 files + the
manifest + the background dispatch by hand. The divergent allFrames /
eligibility are now explicit, asserted config — drift surfaces in the table
test instead of hiding.

Behavior

Unchanged. Same script ids, bundles, frame scopes, persistAcrossSessions,
log strings, and inject-* message types. Net ~255 fewer production LOC.

Testing

• bun run check (biome + eslint) clean
• bun run typecheck clean
• Full suite: 107 suites / 2023 tests pass (the four per-feature registration
  tests are replaced by page-world-hook.test.ts for the generic lifecycle +
  page-world-hooks.test.ts pinning the per-hook config and dispatch routing)
• bun run build succeeds, including the background.js purity canary check;
  all four page-world bundles still emit

🤖 Generated with Claude Code