Insta Toolbox 3.1.0

Distribution notes

• The Windows installer is unsigned and may show a Microsoft SmartScreen warning.
• The macOS packages are ad-hoc signed and are not Apple-notarized.
• Automated CI does not claim current authenticated Instagram compatibility or a completed human screen-reader walkthrough. Consult the 3.1.0 acceptance record for any separately recorded manual evidence.

What's Changed

• Revise README installation steps for clarity by @slaveofsolace in #30
• release: Insta Toolbox 3.1.0 by @slaveofsolace in #31
• docs: remove process narration from public copy by @slaveofsolace in #32
• ci: allow exact-main manual verification by @slaveofsolace in #33
• docs:use-real-install-screenshots by @slaveofsolace in #34

Full Changelog: v3.0.0...v3.1.0