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/redbear-keymapd/source/src/main.rs

@@ -41,7 +41,7 @@ fn main() {
             }
             Err(e) => {
                 log_msg("ERROR", &format!("failed to read request: {}", e));
-                process::exit(1);
+                break;
             }
         };