Use canonical repository for Bridgistic Pages

[Shubochandrosarker]

Summary

• Make the linked Bridgistic repository the source for the bridgistic.app landing page and assets.
• Deploy site edits on main and use both the release version and source commit to detect an already deployed build.
• Keep release-tag deployments for published releases and document the source/deployment behavior.

Validation

• npm.cmd run validate — passed (0 problems, 0 warnings).
• git diff --check — passed.
• WordPressistic live page template candidate PHP lint — passed locally; it is not part of this PR.

After merge, verify the GitHub Pages workflow and confirm the public page reports the expected release and source commit.