refactor: replace array-based expressions with typed class hierarchy

Replace the old Lisp-like array expression representation
(["AND", ["PARAM", ...], ...]) with a class hierarchy rooted in
an abstract Expression class (Literal, Parameter, Binary, Unary,
FunctionCall, Conditional). This gives compile-time type safety
to expression construction, evaluation, and pattern matching.

Key changes:
- New lib/common/expression.ts defines the class hierarchy with
  map/evaluate/toString methods
- Rewrite parser as hand-rolled recursive descent, removing the
  parsimmon dependency
- Extend Path with a colon separator to unify parameter identity
  and attributes into a single address space (e.g.
  "Device.WiFi.SSID.1.Name:writable"). The colon field tracks
  how many trailing segments are attribute qualifiers. PathSet
  rewritten with separate param/attr segment indexes
- Flatten device attribute representation in the UI to
  colon-delimited keys mirroring the new path syntax

test/path-set.ts

@@ -3,67 +3,63 @@ import assert from "node:assert";
 import Path from "../lib/common/path.ts";
 import PathSet from "../lib/common/path-set.ts";
 
-void test("depth", () => {
-  const pathSet = new PathSet();
-  assert.strictEqual(pathSet.depth, 0);
-  pathSet.add(Path.parse(""));
-  assert.strictEqual(pathSet.depth, 1);
-  pathSet.add(Path.parse("a"));
-  assert.strictEqual(pathSet.depth, 2);
-});
-
 void test("add", () => {
   const pathSet = new PathSet();
-  pathSet.add(Path.parse("a"));
-  pathSet.add(Path.parse("a"));
-  assert.strictEqual(pathSet.find(Path.parse("a"), true, true, 99).length, 1);
+  pathSet.add("a");
+  pathSet.add("a");
+  assert.strictEqual(
+    pathSet.findCompat(Path.parse("a"), true, true, 99).length,
+    1,
+  );
 });
 
 void test("get", () => {
   const pathSet = new PathSet();
-  pathSet.add(Path.parse("a.*"));
-  pathSet.add(Path.parse("a.a"));
-  pathSet.add(Path.parse("*.*"));
+  pathSet.add("a.*");
+  pathSet.add("a.a");
+  pathSet.add("*.*");
 
-  assert.strictEqual(pathSet.get(Path.parse("a.*")).toString(), "a.*");
-  assert.strictEqual(pathSet.get(Path.parse("*.a")), null);
+  assert.strictEqual(pathSet.get("a.*").toString(), "a.*");
+  assert.equal(pathSet.get("*.a"), null);
 });
 
 void test("find", () => {
   const pathSet = new PathSet();
-  pathSet.add(Path.parse("a"));
-  pathSet.add(Path.parse("a.*"));
-  pathSet.add(Path.parse("a.a"));
-  pathSet.add(Path.parse("*.a"));
-  pathSet.add(Path.parse("*.*"));
+  pathSet.add("a");
+  pathSet.add("a.*");
+  pathSet.add("a.a");
+  pathSet.add("*.a");
+  pathSet.add("*.*");
 
   assert.deepStrictEqual(
-    pathSet.find(Path.parse(""), true, true, 1).map((p) => p.toString()),
+    pathSet.findCompat(Path.root, true, true, 1).map((p) => p.toString()),
     ["a"],
   );
 
   assert.deepStrictEqual(
-    pathSet.find(Path.parse(""), false, false, 2).map((p) => p.toString()),
+    pathSet.findCompat(Path.root, false, false, 2).map((p) => p.toString()),
     ["a", "a.*", "a.a", "*.a", "*.*"],
   );
 
   assert.deepStrictEqual(
-    pathSet.find(Path.parse("a.*"), false, false).map((p) => p.toString()),
+    pathSet
+      .findCompat(Path.parse("a.*"), false, false)
+      .map((p) => p.toString()),
     ["a.*"],
   );
 
   assert.deepStrictEqual(
-    pathSet.find(Path.parse("a.*"), false, true).map((p) => p.toString()),
+    pathSet.findCompat(Path.parse("a.*"), false, true).map((p) => p.toString()),
     ["a.*", "a.a"],
   );
 
   assert.deepStrictEqual(
-    pathSet.find(Path.parse("a.*"), true, false).map((p) => p.toString()),
+    pathSet.findCompat(Path.parse("a.*"), true, false).map((p) => p.toString()),
     ["a.*", "*.*"],
   );
 
   assert.deepStrictEqual(
-    pathSet.find(Path.parse("a.*"), true, true).map((p) => p.toString()),
+    pathSet.findCompat(Path.parse("a.*"), true, true).map((p) => p.toString()),
     ["a.*", "a.a", "*.a", "*.*"],
   );
 });