cmds.pkg: Add --exact to jw-pkg packages install

Add an additional option -x, which inhibits dependency resolution during
installation of packages.

Signed-off-by: Jan Lindemann <jan@janware.com>
Assisted-by: unsloth/Qwen3.8-27B-GGUF:Q4_K_M with pi.dev v1.4.0

src/python/jw/pkg/cmds/pkg/CmdInstall.py

@@ -26,6 +26,14 @@ class CmdInstall(Cmd):  # export
             action = 'store_true',
             help = "Only update the listed packages, don't install them",
         )
+        parser.add_argument(
+            '-x',
+            '--exact',
+            default = False,
+            action = 'store_true',
+            help = "Install local files directly, without resolving "
+            "dependencies",
+        )
         parser.add_argument(
             '-F',
             '--fixed-strings',
@@ -38,4 +46,8 @@ class CmdInstall(Cmd):  # export
         names = (
             args.names if args.fixed_strings else self.distro.expand_macros(args.names)
         )
-        return await self.distro.install(names, only_update = args.only_update)
+        return await self.distro.install(
+            names,
+            only_update = args.only_update,
+            install_deps = not (args.only_update or args.exact),
+        )