UI: drop Magisk prompt — ResourceMonitor stops probing su

ResourceMonitor.init ran `su -c id` at every ChatActivity launch to see
if root was available, then used root to read /sys/class/kgsl/... and
/sys/bus/platform/devices/soc:qcom,msm-cdsp-rm/... for GPU/NPU usage %.
That probe was the only thing still triggering the Magisk auth dialog
on each app start after the no-root LLM migration.

Remove the root probe and the execRoot helper. GPU/NPU reads now return
-1 (UI already renders "—" for negative values). The non-root
/sys/class/kgsl/kgsl-3d0/gpubusy path is kept as a best-effort — it's
world-readable on some devices, silently fails otherwise. CPU and RAM
readouts are unaffected (never needed root).

Dead-code `su -c ...` calls remain in Qwen3TtsEngine (hexStartRunner,
hexStartCpRunner, hexStopRunner, etc.) and WhisperNpuSttEngine, but all
are gated behind fallback paths that don't execute under the current
PTE-only config (talkerPteModule != null && cpPteModule != null short-
circuits before any su call). Left in place to avoid churning the TTS
Hexagon fallback; can be purged in a later cleanup pass if needed.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

kazeia-android/app/src/main/java/com/kazeia/ui/ResourceMonitor.kt

@@ -18,17 +18,12 @@ class ResourceMonitor(private val context: Context) {
     private var prevIdle = 0L
     private var prevGpuBusy = 0L
     private var prevGpuTotal = 0L
-    private var hasRoot = false
 
-    init {
-        // Test root access once
-        hasRoot = try {
-            val p = Runtime.getRuntime().exec(arrayOf("su", "-c", "id"))
-            val result = p.inputStream.bufferedReader().readText()
-            p.waitFor()
-            result.contains("uid=0")
-        } catch (_: Exception) { false }
-    }
+    // No-root deployment (2026-04-14): the previous `su -c id` probe used to
+    // enable GPU/NPU sysfs reads via root, but it also triggered a Magisk
+    // prompt on every ChatActivity launch. The whole pipeline now runs in
+    // the app process so root is never needed — GPU/NPU usage is reported
+    // as -1 (UI shows "—") and the dashboard shows CPU + RAM only.
 
     fun snapshot(): ResourceSnapshot {
         return ResourceSnapshot(
@@ -67,7 +62,9 @@ class ResourceMonitor(private val context: Context) {
     }
 
     private fun readGpu(): Float {
-        // Try direct read first (works on some devices)
+        // Non-root path: some devices expose /sys/class/kgsl/kgsl-3d0/gpubusy
+        // as world-readable. If it's locked down (most SELinux configs do),
+        // just return -1 — no root fallback, no Magisk prompt.
         try {
             val content = File("/sys/class/kgsl/kgsl-3d0/gpubusy").readText().trim()
             val parts = content.split("\\s+".toRegex())
@@ -81,38 +78,14 @@ class ResourceMonitor(private val context: Context) {
                 if (dt > 0) return (db * 100f / dt).coerceIn(0f, 100f)
             }
         } catch (_: Exception) {}
-
-        // Try with root
-        if (hasRoot) {
-            try {
-                val content = execRoot("cat /sys/class/kgsl/kgsl-3d0/gpu_busy_percentage").trim()
-                val pct = content.replace("%", "").trim().toFloatOrNull()
-                if (pct != null) return pct.coerceIn(0f, 100f)
-            } catch (_: Exception) {}
-        }
-
         return -1f
     }
 
     private fun readNpu(): Float {
-        // NPU doesn't have a standard busy metric
-        // Use CDSP (compute DSP) load as proxy if available
-        if (hasRoot) {
-            try {
-                // Check if CDSP is active by reading vote count
-                val vote = execRoot("cat /sys/bus/platform/devices/soc:qcom,msm-cdsp-rm/cdsp_rm/cpu_vote 2>/dev/null").trim()
-                if (vote.isNotEmpty()) {
-                    val v = vote.toIntOrNull() ?: 0
-                    return if (v > 0) 100f else 0f
-                }
-            } catch (_: Exception) {}
-
-            try {
-                // Alternative: check fastrpc activity
-                val stat = execRoot("cat /proc/fastrpc 2>/dev/null || echo none").trim()
-                if (stat != "none" && stat.isNotEmpty()) return 50f
-            } catch (_: Exception) {}
-        }
+        // NPU usage reporting required root sysfs reads (cdsp_rm/cpu_vote,
+        // /proc/fastrpc) that always triggered a Magisk prompt. Removed with
+        // the no-root migration — no equivalent public API exists, so the
+        // UI just shows "—" for NPU load.
         return -1f
     }
 
@@ -134,12 +107,4 @@ class ResourceMonitor(private val context: Context) {
         } catch (_: Exception) { return 0 }
     }
 
-    private fun execRoot(cmd: String): String {
-        return try {
-            val p = Runtime.getRuntime().exec(arrayOf("su", "-c", cmd))
-            val result = p.inputStream.bufferedReader().readText()
-            p.waitFor()
-            result
-        } catch (_: Exception) { "" }
-    }
 }