fix: use extraMetadata.version for 4-part display, semver for electron-builder

[tech-stack-studios]

Fixes the CI build failure caused by electron-builder rejecting 4-part versions.

Root cause: electron-builder validates package.json's version field against semver, which only allows 3 parts (MAJOR.MINOR.PATCH).

Fix:

• version stays as 3-part semver (MAJOR.ALPHA.BETA) — what electron-builder uses for the .deb package name
• build.extraMetadata.version holds the full 4-part version (MAJOR.ALPHA.BETA.BUILD) — electron-builder writes this into the packaged app's package.json, so app.getVersion() returns the 4-part display version
• CI bump script now reads/writes extraMetadata.version for the full version, and syncs the 3-part version field on alpha/beta merges
• Seed values reset to version: 1.0.0 and extraMetadata.version: 1.0.0.0