Verify each finding against the current code and only fix it if needed.

Inline comments:
In `@packages/runtime-vapor/src/components/KeepAlive.ts`:
- Line 153: Do not reset keepAliveInstance.exposed to null during HMR; remove
the assignment (or restore the previous exposed value) so the exposed reference
remains intact across rerenders—locate the line that sets
keepAliveInstance.exposed = null in KeepAlive.ts and either delete that
statement or replace it with logic that preserves the existing exposed value
instead of assigning null.

In `@packages/runtime-vapor/src/components/Transition.ts`:
- Around line 91-94: The expose() calls in Transition and TransitionGroup are
violating the FunctionalVaporComponent signature because expose is defined as
expose: <T extends Record<string, any> = Exposed>(exposed: T) => void but the
components call expose() with no arg; fix by making the parameter optional on
the FunctionalVaporComponent signature (change to expose: <T extends
Record<string, any> = Exposed>(exposed?: T) => void) so callers like Transition
and TransitionGroup can call expose() without error, or alternatively update the
callers (Transition and TransitionGroup) to call expose({}) instead; update the
signature in the component type (FunctionalVaporComponent / component.ts) if you
want a systemic fix, or change the two expose() calls in Transition and
TransitionGroup to expose({}) if you prefer a localized change.

---

Duplicate comments:
In `@packages/runtime-vapor/src/components/TransitionGroup.ts`:
- Around line 60-62: The // `@ts-expect-error` on the setup call is hiding an
untyped context; fix it by typing the setup context instead of suppressing
errors: import SetupContext from 'vue' (or use the correct SetupContext generic)
and change the signature to setup(props: TransitionGroupProps, { slots, expose
}: SetupContext) (and call expose() as before), removing the comment; apply the
same shared typing fix to the matching setup in Transition.ts so both callsites
use the correctly typed SetupContext.