Add Overworld tile search command and enhance related documentation

- Implemented `overworld-find-tile` command in the agent for searching tiles by ID.
- Updated `README.md` and `AGENT-ROADMAP.md` to reflect new command and usage.
- Enhanced `overworld_inspect` module with tile matching functionality.

src/cli/handlers/agent/commands.h

@@ -31,6 +31,9 @@ absl::Status HandleResourceListCommand(
 absl::Status HandleDungeonListSpritesCommand(
 	const std::vector<std::string>& arg_vec,
 	Rom* rom_context = nullptr);
+absl::Status HandleOverworldFindTileCommand(
+	const std::vector<std::string>& arg_vec,
+	Rom* rom_context = nullptr);
 absl::Status HandleOverworldDescribeMapCommand(
 	const std::vector<std::string>& arg_vec,
 	Rom* rom_context = nullptr);