feat(doorbell): add staged boot sequence and refactor main loop

hk.pkl

@@ -0,0 +1,30 @@
+amends "package://github.com/jdx/hk/releases/download/v1.36.0/hk@1.36.0#/Config.pkl"
+import "package://github.com/jdx/hk/releases/download/v1.36.0/hk@1.36.0#/Builtins.pkl"
+
+// Only process files in sketches/ directory (excluding vendor/)
+glob = List("sketches/**", "!sketches/**/vendor/**")
+
+local linters = new Mapping<String, Step> {
+    ["format"] = Builtins.clang_format
+
+    ["trailing-whitespace"] = Builtins.trailing_whitespace
+
+    ["mixed-line-ending"] = Builtins.mixed_line_ending
+
+    ["check-merge-conflict"] = Builtins.check_merge_conflict
+}
+
+hooks {
+    ["pre-commit"] {
+        fix = true
+        stash = "git"
+        steps = linters
+    }
+    ["fix"] {
+        fix = true
+        steps = linters
+    }
+    ["check"] {
+        steps = linters
+    }
+}