feat: improve terminal install, recovery, and proot compatibility

- switch terminal setup to a staged install pipeline with cache markers, native download actions, and selective uninstall behavior so repeated installs and repairs avoid unnecessary downloads
- replace process-only startup checks with HTTP readiness probing, add automatic repair when axs is running but not reachable, and retry terminal creation after refreshing the embedded axs binary on PTY open failures
- improve Alpine bootstrap scripts by hardening package checks, moving command-not-found handling through /bin/sh, exposing the acode CLI as shell functions, enabling allow-any-origin for local requests, disabling proot seccomp, and removing --sysvipc for kernel stability
- unify terminal default settings and validation for font options, ligatures, image support, and letter spacing, and improve terminal resize and mount behavior around fit timing and observer updates
- persist terminal sessions and active tabs, clean up failed terminal tabs more aggressively, and automatically recover from relocation or symbol resolution failures by reinstalling the runtime when needed
- expose copyAsset from the system bridge for debug axs refresh flows, keep Android executor download support wired through the JS bridge, reduce noisy auth logging for expected unauthenticated states, and update package-lock.json to reflect the integrated dependency state

Author: 埃博拉酱