dissolve app/ into repo root (D-056)

Single Flutter package at the repo root. All code, tests, assets,
and platform directories moved from app/ to root. Package renamed
from clide_app to clide — all imports rewritten. Merged pubspec
combines core (ffi) and app (flutter, yaml, xterm) dependencies.
Makefile simplified: no APP_PRESENT conditionals, no cd, no daemon
lifecycle. 317 tests pass.

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

test/builtin/claude/session_naming_test.dart

@@ -0,0 +1,27 @@
+import 'package:clide/builtin/claude/src/session_naming.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+void main() {
+  group('claude session naming', () {
+    test('primary name is deterministic per repo path', () {
+      final a = primarySessionName('/home/me/clide');
+      final b = primarySessionName('/home/me/clide');
+      expect(a, b);
+      expect(a, startsWith('clide-claude-'));
+    });
+
+    test('different repos yield different primaries', () {
+      final a = primarySessionName('/home/me/clide');
+      final b = primarySessionName('/home/me/other');
+      expect(a, isNot(b));
+    });
+
+    test('secondary names carry the N suffix', () {
+      final p = primarySessionName('/home/me/clide');
+      final s1 = secondarySessionName('/home/me/clide', 1);
+      final s2 = secondarySessionName('/home/me/clide', 2);
+      expect(s1, '$p-1');
+      expect(s2, '$p-2');
+    });
+  });
+}