feat: add cp command for file copy operations

Add 'hypeman cp' command for copying files to/from running instances,
with docker cp compatible semantics:

Features:
- Copy files and directories to instances: hypeman cp file.txt instance:/path
- Copy from instances: hypeman cp instance:/path file.txt
- STDIN/STDOUT streaming with '-' argument for tar archives
- Recursive directory copying with proper tar packing/unpacking
- Symlink handling with --follow-links flag
- Archive mode (-a) to preserve UID/GID ownership
- Quiet mode (-q) to suppress progress output
- Docker cp path resolution semantics:
  - SRC_PATH/. copies contents, not the directory itself
  - Trailing slash handling for directory vs file detection

The command communicates with the API server via WebSocket,
streaming file data as binary chunks with JSON metadata headers.

Author: rgarcia

go.mod

@@ -12,7 +12,7 @@ require (
 	github.com/gorilla/websocket v1.5.3
 	github.com/itchyny/json2yaml v0.1.4
 	github.com/muesli/reflow v0.3.0
-	github.com/onkernel/hypeman-go v0.7.0
+	github.com/onkernel/hypeman-go v0.7.1-0.20251223043134-e172b69eca2b
 	github.com/tidwall/gjson v1.18.0
 	github.com/tidwall/pretty v1.2.1
 	github.com/urfave/cli-docs/v3 v3.0.0-alpha6
@@ -74,3 +74,5 @@ require (
 	google.golang.org/genproto/googleapis/rpc v0.0.0-20250825161204-c5933d9347a5 // indirect
 	google.golang.org/grpc v1.75.1 // indirect
 )
+
+replace github.com/onkernel/hypeman-go => ../hypeman-go

go.sum

@@ -105,8 +105,6 @@ github.com/muesli/reflow v0.3.0 h1:IFsN6K9NfGtjeggFP+68I4chLZV2yIKsXJFNZ+eWh6s=
 github.com/muesli/reflow v0.3.0/go.mod h1:pbwTDkVPibjO2kyvBQRBxTWEEGDGq0FlB1BIKtnHY/8=
 github.com/muesli/termenv v0.16.0 h1:S5AlUN9dENB57rsbnkPyfdGuWIlkmzJjbFf0Tf5FWUc=
 github.com/muesli/termenv v0.16.0/go.mod h1:ZRfOIKPFDYQoDFF4Olj7/QJbW60Ol/kL1pU3VfY/Cnk=
-github.com/onkernel/hypeman-go v0.7.0 h1:KUeY4VGJtStA4+zkPtx7eDCO3rSznbIVoj4U6l+g50Q=
-github.com/onkernel/hypeman-go v0.7.0/go.mod h1:BPT1yh0gbby1E+As/xLM3GVjw7752+2C5SaEiJV9rRc=
 github.com/opencontainers/go-digest v1.0.0 h1:apOUWs51W5PlhuyGyz9FCeeBIOUDA/6nW8Oi/yOhh5U=
 github.com/opencontainers/go-digest v1.0.0/go.mod h1:0JzlMkj0TRzQZfJkVvzbP0HBR3IKzErnv2BNG4W4MAM=
 github.com/opencontainers/image-spec v1.1.1 h1:y0fUlFfIZhPF1W537XOLg0/fcx6zcHCJwooC2xJA040=

pkg/cmd/cmd.go

@@ -68,6 +68,7 @@ func init() {
 		},
 		Commands: []*cli.Command{
 			&execCmd,
+			&cpCmd,
 			&pullCmd,
 			&pushCmd,
 			&runCmd,