fix(live-debugger): exclude params from locals in instrumented code

[watson]

What and why?

The live debugger build plugin was duplicating function parameters in the snapshot's locals section. When an instrumented function was captured at its return point, the locals object sent to the browser SDK contained both the function's local variable declarations and its parameters — even though parameters were already captured separately in the arguments object. This caused redundant data in debugger snapshots.

How?

Transform change (scopeTracker / index.ts):

• Changed exitVars (the locals helper) from getVariableNames(node, true, true) to getVariableNames(node, false, true), so it only collects local variable declarations — not function parameters.
• When there are no local variables, the locals helper and its argument to $dd_return are omitted entirely instead of passing an empty object, reducing instrumented bundle size.
• When there are no function parameters, the args helper is also omitted and the argument to $dd_entry/$dd_return/$dd_throw is dropped. If locals are present but params are not, undefined is passed as a positional placeholder for args in $dd_return.

Generated output for each case:

Scenario	$dd_entry / $dd_throw	$dd_return
No params, no locals	(probes, this)	(probes, rv, this)
No params, has locals	(probes, this)	(probes, rv, this, undefined, $dd_l())
Has params, no locals	(probes, this, $dd_e())	(probes, rv, this, $dd_e())
Has params, has locals	(probes, this, $dd_e())	(probes, rv, this, $dd_e(), $dd_l())

Note: This change requires a corresponding update in the browser-sdk to default the args and locals parameters to {} in onEntry, onReturn, and onThrow, so that omitted arguments are handled gracefully.

[watson]

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Learn more

• fix(live-debugger): emit correct sourcemaps for instrumented functions #337
• fix(live-debugger): exclude params from locals in instrumented code #335 👈 (View in Graphite)
• Source build version from shared metadata.version #326
• master

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