refactor(dependency): strip gated dead code, bump to v4.0.0

[MahtraDR]

Summary

• Remove all 7 gated blocks that are dead code on core lich 5.17.2+ (ArgParser, SetupFiles, ScriptManager, custom_require, make_map_edits, DR startup, get_settings/get_data globals)
• Remove deprecated autostart/stop_autostart/dependency_status stubs (verified zero callers across dr-scripts, gs-scripts, and lich-5)
• Remove one-shot Settings['autostart'] migration (completed long ago)
• Remove redundant parse_args/display_args wrappers (core provides identical ones via global_defs.rb)
• Remove fully dead boot sequence (every branch is a no-op on core)
• Bump version to 4.0.0, require lich >= 5.17.2
• Update spec file: keep tests for remaining runtime helpers, remove tests for deleted code

Net: -1,952 lines (+84 / -2,036). dependency.lic is now ~110 lines.

What remains are runtime helpers (bankbot, slackbot, reportbot, hometown, verify_script, format_name) that dr-scripts still actively call. These are candidates for a future upstream into core lich.

Verification

All claims independently verified across all three repos (dr-scripts, gs-scripts, lich-5):

• All 7 sentinel constants confirmed defined and set to true in core (arg_parser.rb, setup_files.rb, global_defs.rb, map_base.rb, startup.rb)
• Every ungated helper confirmed to have active callers (or confirmed dead via git history)
• custom_require callers (gate.lic, performance-monitor.lic) confirmed safe -- both have respond_to?(:start_scripts_if_available) guards
• Deprecated stubs confirmed to have zero callers
• Boot sequence confirmed fully dead (all respond_to? checks return false)

Companion PR

autostart.lic cleanup (gs-scripts): removes legacy DR dependency path and respond_to? guards that are now always true on 5.17.2+.

Test plan

• bundle exec rspec spec/dependency_spec.rb -- 43 examples, 0 failures
• Verify dependency loads cleanly in-game on lich 5.17.2+
• Verify bankbot, slackbot, trade.lic hometown functions work
• Verify autostart.lic still runs dependency and starts DR scripts

🤖 Generated with Claude Code

[MahtraDR]

Retargeting to upstream elanthia-online/dr-scripts