The debug tool ran validateLaunchProgram before adapter selection and
rejected any directory program with `launch program resolves to a
directory`, while dlv's default `mode=debug` requires a Go package
path (a directory or .go source file). Every Go-module launch failed:
passing the module dir was rejected outright, and passing the compiled
binary failed at dlv with `not a valid go module`.
- Add `acceptsDirectoryProgram` to DapAdapterConfig/DapResolvedAdapter
and flag dlv in dap/defaults.json.
- In DebugTool.execute(launch), resolve the adapter first, then call
validateLaunchProgram with the resolved adapter — the directory
rejection only fires when the adapter does not advertise the flag.
- Add resolveLaunchOverrides in dap/config.ts: for dlv, derive `mode`
from the program shape (directory or .go file → debug; other file
→ exec). Plumbed through DapLaunchSessionOptions.extraLaunchArguments
and spread between adapter.launchDefaults and the hard-coded launch
fields in session.ts.
- Refresh tests: cover the no-dir-support adapter rejection, dlv on a
package directory keeping mode=debug, and dlv on a binary switching
to mode=exec.
Fixes#2020
roboomp
1745529368