Fix interactive input by using Console.readLine instead of Process.exec

Process.exec uses popen(cmd, "r") which creates a read-only pipe where
the subprocess stdin is disconnected from the terminal. Console.readLine
reads directly from the parent process stdin via fgets, fixing all
interactive prompts (askConfirm, askInput, choice menus).

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

cli/pal.lux

@@ -128,10 +128,10 @@ fn printStatusLine(name: String, state: String, detail: String): Unit with {Proc
 }
 
 // Ask for confirmation: returns true if user confirms
-fn askConfirm(question: String, defaultYes: Bool): Bool with {Process} = {
+fn askConfirm(question: String, defaultYes: Bool): Bool with {Console, Process} = {
     let prompt = if defaultYes then " [Y/n] " else " [y/N] "
     let ignore = Process.exec("printf '%s%s' \"" + question + "\" \"" + prompt + "\" >&2")
-    let response = String.trim(Process.exec("head -n1 </dev/tty"))
+    let response = String.trim(Console.readLine())
     let lower = execQuiet("echo '" + response + "' | tr A-Z a-z")
     if String.length(lower) == 0 then
         defaultYes
@@ -148,13 +148,13 @@ fn askConfirm(question: String, defaultYes: Bool): Bool with {Process} = {
 }
 
 // Ask for text input with a default value
-fn askInput(prompt: String, defaultVal: String): String with {Process} = {
+fn askInput(prompt: String, defaultVal: String): String with {Console, Process} = {
     let display = if String.length(defaultVal) > 0 then
         "printf '%s [%s]: ' \"" + prompt + "\" \"" + defaultVal + "\" >&2"
     else
         "printf '%s: ' \"" + prompt + "\" >&2"
     let ignore = Process.exec(display)
-    let input = String.trim(Process.exec("head -n1 </dev/tty"))
+    let input = String.trim(Console.readLine())
     if String.length(input) == 0 then defaultVal else input
 }
 
@@ -302,7 +302,7 @@ fn showMiniLogo(): Unit with {Process} = {
 // Welcome flow (Interactive)
 // =============================================================================
 
-fn showInteractiveWelcome(): Unit with {Process} = {
+fn showInteractiveWelcome(): Unit with {Console, Process} = {
     print("")
     showLogo()
     print("")
@@ -325,7 +325,7 @@ fn showInteractiveWelcome(): Unit with {Process} = {
     print("")
 
     let ignore8 = Process.exec("printf 'Choice [1]: ' >&2")
-    let choice = String.trim(Process.exec("head -n1 </dev/tty"))
+    let choice = String.trim(Console.readLine())
 
     match choice {
         "2" => {
@@ -765,7 +765,7 @@ fn doServerUnmount(): Unit with {Process} = {
 // Export/Import
 // =============================================================================
 
-fn doExport(): Unit with {Process} = {
+fn doExport(): Unit with {Console, Process} = {
     print("")
     let timestamp = execQuiet("date +%Y-%m-%d")
     let exportFile = "pal-export-" + timestamp + ".tar.zst"
@@ -790,7 +790,7 @@ fn doExport(): Unit with {Process} = {
     print("")
 }
 
-fn doImport(archivePath: String): Unit with {Process} = {
+fn doImport(archivePath: String): Unit with {Console, Process} = {
     print("")
 
     if String.length(archivePath) == 0 then {
@@ -974,7 +974,7 @@ fn showCompactStatus(): Unit with {Process} = {
 // Health check (default command)
 // =============================================================================
 
-fn showHealthCheck(): Unit with {Process} = {
+fn showHealthCheck(): Unit with {Console, Process} = {
     // Check if this is an interactive terminal
     let isTty = execQuiet("test -t 0 && echo yes || echo no")
 
@@ -1225,7 +1225,7 @@ fn showOnboardSummary(deviceName: String): Unit with {Process} = {
     print("")
 }
 
-fn doOnboardSteps(): Unit with {Process} = {
+fn doOnboardSteps(): Unit with {Console, Process} = {
     // ── Step 1: Device ──────────────────────────────────────────────────
     let ignore = Process.exec("printf '\\033[1m── Step 1: Device ──\\033[0m\\n\\n' >&2")
 
@@ -1273,7 +1273,7 @@ fn doOnboardSteps(): Unit with {Process} = {
     print("")
 
     let ignore8 = Process.exec("printf 'Choice [3]: ' >&2")
-    let configChoice = String.trim(Process.exec("head -n1 </dev/tty"))
+    let configChoice = String.trim(Console.readLine())
     print("")
 
     match configChoice {
@@ -1451,7 +1451,7 @@ fn doOnboardSteps(): Unit with {Process} = {
     } else ()
 }
 
-fn doOnboard(): Unit with {Process} = {
+fn doOnboard(): Unit with {Console, Process} = {
     print("")
 
     if isInitialized() then {
@@ -1620,7 +1620,7 @@ fn showServerHelp(): Unit with {Process} = {
 // Main
 // =============================================================================
 
-fn main(): Unit with {Process} = {
+fn main(): Unit with {Console, Process} = {
     let args = Process.args()
     let cmd = match List.get(args, 1) {
         Some(c) => c,