Rewrite marketing & docs copy for LoopOver

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Problem: The README, the docs site's route content, and the top-level community files (contributing guide, security policy, support policy, code of conduct) all refer to the product by its old name throughout.

Area: Docs

Proposal: Update copy across these surfaces to lead with "LoopOver." A brief one-line continuity note ("formerly gittensory") near the top of the README is reasonable so existing readers aren't confused. Do not touch references to the separate gittensor network — that's a different brand that is never rebranded here — and do not edit the changelog file in this PR (standing house rule; the one rebrand-related changelog entry is handled separately, in the cleanup step).

Deliverables:

• Updated README, docs site content, contributing guide, security policy, support policy, and code of conduct.

Acceptance criteria:

• No remaining product-name references to the old brand in the files above.
• All internal links in the updated files still resolve correctly.
• References to the separate gittensor network are left exactly as they were.

Test scenarios:

• Build the docs site locally and spot-check navigation and rendered pages.
• Run a link-check pass across the updated files.

Resources:

• The docs site's route files (dozens of files under the UI app's docs routes).
• Top-level community health files at the repo root.

Boundaries:

• Never hand-edit the changelog file in a normal PR.
• Leave every reference to the separate gittensor network's own domain/name untouched.

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Part of #4761.

[linear-code]

JSO-3435