chore(config): Refactor Emacs config for cross-platform compatibility

Add Android/Termux support with `*is-android*` constant and
conditional GUI/terminal initialization. Remove maximized frame
defaults and custom.el. Replace corfu with corfu-terminal in
TTY. Add god-mode to terminal config with line number sync. Update
org agenda to use org-ql blocks with super-agenda grouping. Switch
solarized-theme to fork. Clean up redundant functions and unify
keyboard bindings across environments.

lisp/init-const.el

@@ -9,6 +9,7 @@
 (defconst *is-linux* (eq system-type 'gnu/linux))
 (defconst *is-windows* (or (eq system-type 'ms-dos)
                            (eq system-type 'windows-nt)))
+(defconst *is-android* (if (getenv "TERMUX_VERSION") t nil))
 
 (if *is-windows*
     (progn