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>

assets/queries/cpp.scm

@@ -0,0 +1,77 @@
+; Functions
+
+(call_expression
+  function: (qualified_identifier
+    name: (identifier) @function))
+
+(template_function
+  name: (identifier) @function)
+
+(template_method
+  name: (field_identifier) @function)
+
+(template_function
+  name: (identifier) @function)
+
+(function_declarator
+  declarator: (qualified_identifier
+    name: (identifier) @function))
+
+(function_declarator
+  declarator: (field_identifier) @function)
+
+; Types
+
+((namespace_identifier) @type
+ (#match? @type "^[A-Z]"))
+
+(auto) @type
+
+; Constants
+
+(this) @variable.builtin
+(null "nullptr" @constant)
+
+; Modules
+(module_name
+  (identifier) @module)
+
+; Keywords
+
+[
+ "catch"
+ "class"
+ "co_await"
+ "co_return"
+ "co_yield"
+ "constexpr"
+ "constinit"
+ "consteval"
+ "delete"
+ "explicit"
+ "final"
+ "friend"
+ "mutable"
+ "namespace"
+ "noexcept"
+ "new"
+ "override"
+ "private"
+ "protected"
+ "public"
+ "template"
+ "throw"
+ "try"
+ "typename"
+ "using"
+ "concept"
+ "requires"
+ "virtual"
+ "import"
+ "export"
+ "module"
+] @keyword
+
+; Strings
+
+(raw_string_literal) @string