fix: udev-shim panic, sessiond duplicate, scheme Bad-fd handling

- udev-shim: replace .expect() with graceful errors (no more panic on Broken pipe)
- P4-initfs: remove duplicate sessiond (conflicted with config)
- accessibility/ime/keymapd: break instead of exit(1) on EBADF
- P6 driver patches rebased
- Docs: archive old reports, add implementation master plan

local/recipes/system/thermald/source/src/fan.rs

@@ -0,0 +1,33 @@
+pub struct FanControl {
+    pub fan_speed: u8,
+    pub max_speed: u8,
+    pub auto_mode: bool,
+    pub trip_temp_c: f64,
+}
+
+impl FanControl {
+    pub fn new() -> Self { Self { fan_speed: 50, max_speed: 100, auto_mode: true, trip_temp_c: 60.0 } }
+
+    pub fn set_speed(&mut self, pct: u8) { self.fan_speed = pct.min(self.max_speed); self.auto_mode = false; }
+
+    pub fn update_from_temp(&mut self, temp_c: f64) {
+        if !self.auto_mode { return; }
+        self.fan_speed = if temp_c < 40.0 { 20 }
+            else if temp_c < 50.0 { 40 }
+            else if temp_c < 60.0 { 60 }
+            else if temp_c < 70.0 { 80 }
+            else { 100 };
+    }
+
+    pub fn emergency_full(&mut self) { self.fan_speed = 100; self.auto_mode = false; }
+
+    pub fn write_acpi_fan(&self, fan_idx: u32) -> bool {
+        let path = format!("/scheme/acpi/fan/{}/speed", fan_idx);
+        fs::write(&path, format!("{}", self.fan_speed)).is_ok()
+    }
+
+    pub fn read_acpi_fan_state(fan_idx: u32) -> Option<u8> {
+        fs::read_to_string(format!("/scheme/acpi/fan/{}/state", fan_idx)).ok()
+            .and_then(|s| s.trim().parse().ok())
+    }
+}