our-basic CHANGELOG -- calog's modifications to upstream MY-BASIC
================================================================

Every change below is marked in-source with the comment tag "[calog fork]".
Baseline: ourBasic.c.upstream (pristine upstream MY-BASIC). Run
  diff ourBasic.c.upstream ourBasic.c
to see the full patch set.

Concurrency
  - The _mb_allocated allocation counter was changed from `volatile` to `_Atomic`,
    so independent interpreters (one per calog context thread) can be created and
    destroyed concurrently without racing the counter. Execution already runs
    unlocked; only lifecycle is serialized, in the adapter.

Memory
  - A my-basic routine (lambda) popped as a refused/errored native argument is now
    disposed on the error path so its scope is not leaked. (In the adapter's
    arg-marshal loop, src/mybasic/mybasicAdapter.c.)

First-class routines -- the reason for the fork
  - Bare-def-as-value: in _calc_expression, a routine identifier NOT followed by
    '(' now pushes the routine as an operand (a first-class value) instead of
    raising "Open bracket expected". A script can now pass a `def` (or a lambda) to
    a native and store it in a variable -- required for cross-engine callbacks
    (pubsub / timer / export). It mirrors the array-index branch beside it; calls,
    recursion, and closures are unchanged.
  - mb_eval_routine_cold(): a new public entry (declared in ourBasic.h) that invokes
    a routine value from an IDLE interpreter -- one with no live call frame. It
    supplies the last AST node as a clean return landing and passes arguments
    directly. calog uses it to fire script callbacks that were registered earlier
    and delivered when the interpreter is otherwise idle.

Constraint: a callback must be a TOP-LEVEL def/lambda (persistent scope); a routine
local to a function would dangle once that function returns -- the same rule every
engine's closures follow.

Verified: full calog `make test` (28 binaries, 0 failed) plus the my-basic engine
suite (testMyBasic / testEngineMyBasic / testPolyglot / testLoad / testTask),
ASan/UBSan-clean, with def and lambda callbacks firing via timer/pubsub/export and
cross-engine (a Lua task calling a my-basic def).