fix: Only check first non-flag arg against NonDownloadCommands

Scanning all args caused false proxy bypasses when package names or
script arguments matched a NonDownloadCommands entry. For example:
- npm exec test → "test" matched, proxy incorrectly skipped
- npm update config → "config" matched, proxy skipped
- npm publish --tag version → "version" matched, proxy skipped

Fix by checking only the first non-flag argument (the subcommand).
If it is not in NonDownloadCommands we break immediately, so trailing
args never influence the classification. Applied to all four parsers:
npm, pip/pip3, uv, and poetry.

Regression tests added for the false positive cases.

packagemanager/npm.go

@@ -134,12 +134,18 @@ func (npm *npmPackageManager) ParseCommand(args []string) (*ParsedCommand, error
 	}
 
 	if installCmdIndex == -1 {
-		// Check if this is a known non-download command (e.g., npm ls, npm outdated).
-		// Unknown commands are treated as potential downloads — fail safe.
+		// Check only the first non-flag arg (the subcommand) against NonDownloadCommands.
+		// Scanning all args would cause false positives when package names or script
+		// arguments happen to match a known non-download command (e.g. `npm exec test`,
+		// `npm update config`, `npm publish --tag version`).
 		for _, arg := range args {
+			if strings.HasPrefix(arg, "-") {
+				continue
+			}
 			if slices.Contains(npm.Config.NonDownloadCommands, arg) {
 				return &ParsedCommand{Command: command, IsKnownNonDownloadCommand: true}, nil
 			}
+			break
 		}
 
 		return &ParsedCommand{Command: command}, nil

packagemanager/npm_test.go

@@ -561,6 +561,28 @@ func TestNpmProxyBehavior(t *testing.T) {
 			isKnownNonDownloadCmd: true,
 			isInstallationCommand: false,
 		},
+		// False positive regression: package/script names matching NonDownloadCommands words
+		{
+			name:                  "npm exec test — proxy runs (test is package arg, not subcommand)",
+			pm:                    func() (*npmPackageManager, error) { return NewNpmPackageManager(DefaultNpmPackageManagerConfig()) },
+			command:               "npm exec test",
+			isKnownNonDownloadCmd: false,
+			isInstallationCommand: false,
+		},
+		{
+			name:                  "npm update config — proxy runs (config is package name, not subcommand)",
+			pm:                    func() (*npmPackageManager, error) { return NewNpmPackageManager(DefaultNpmPackageManagerConfig()) },
+			command:               "npm update config",
+			isKnownNonDownloadCmd: false,
+			isInstallationCommand: false,
+		},
+		{
+			name:                  "npm publish --tag version — proxy runs (version is flag value, not subcommand)",
+			pm:                    func() (*npmPackageManager, error) { return NewNpmPackageManager(DefaultNpmPackageManagerConfig()) },
+			command:               "npm publish --tag version",
+			isKnownNonDownloadCmd: false,
+			isInstallationCommand: false,
+		},
 		// Unknown commands default to proxy running (fail safe)
 		{
 			name:                  "unknown npm subcommand — proxy runs (fail safe)",

packagemanager/pypi.go

@@ -149,9 +149,13 @@ func (p *pipCommandParser) ParseCommand(args []string) (*ParsedCommand, error) {
 
 	if installCmdIndex == -1 {
 		for _, arg := range args {
+			if strings.HasPrefix(arg, "-") {
+				continue
+			}
 			if slices.Contains(p.config.NonDownloadCommands, arg) {
 				return &ParsedCommand{Command: command, IsKnownNonDownloadCommand: true}, nil
 			}
+			break
 		}
 
 		return &ParsedCommand{Command: command}, nil
@@ -376,9 +380,13 @@ func (p *poetryCommandParser) ParseCommand(args []string) (*ParsedCommand, error
 
 	if installCmdIndex == -1 {
 		for _, arg := range args {
+			if strings.HasPrefix(arg, "-") {
+				continue
+			}
 			if slices.Contains(p.config.NonDownloadCommands, arg) {
 				return &ParsedCommand{Command: command, IsKnownNonDownloadCommand: true}, nil
 			}
+			break
 		}
 
 		return &ParsedCommand{Command: command}, nil