GeezerVison

Creating a lambda currently applies its body's state transitions to
captured objects. For example, `Runnable later = () ->
manager.addEdit(null); manager.undo();` passes even though the callback
may never run. Check lambda bodies in an isolated context so their
assignments, branch facts, and try transitions do not change the
surrounding execution.

Forget invocation-time assumptions about mutable captures while
preserving guards on effectively final primitive captures. Restore
variable instances, shared refinements, paths, and enclosing try
recorders even after a body diagnostic. The regressions cover local and
field callbacks, nested lambdas, try/catch/finally, invalid bodies,
primitive guards, and the anonymous-class reproducer already fixed by
#326.

Callback invocation summaries remain unsupported: `listener.run()` does
not apply effects to its captures. Receiver-call checking and lambda
return boundaries are handled separately by #384 and #385.

Validation: `mvn test -pl liquidjava-verifier -am` (389 tests, no
failures) before the final blank-local capture precision adjustment.
Both focused fixtures were rerun on the final code: the passing fixture
verifies, including blank locals assigned before capture, and all seven
expected failing-fixture diagnostic titles and positions match.

Fixes #341.