chore: fix gittensory -> loopover rename residue

[JSONbored]

Part of #6065. Small, mechanical, low-risk.

Problem

Found while auditing the review-comment stack:

• README.md:3 reads "Formerly LoopOver." -- self-referential, should read "Formerly Gittensory."
• README.md:9 docs badge still points at gittensory.aethereal.dev.
• The legacy comment renderer's HTML marker is still <!-- gittensory-pr-panel:v1 --> (packages/loopover-engine/src/signals/engine.ts ~4543).
• config/examples/README.md and TEMPLATES.md still refer to filenames as gittensory.yml when the actual files in that directory are loopover.full.yml etc.

Proposed fix

• Fix the two README.md prose/badge issues directly.
• Fix the config/examples doc filename references directly.
• For the HTML marker constant: rename with care -- src/github/comments.ts's markerAliases() matches multiple marker strings for backward compatibility with in-flight comments across the rename; confirm whether adding a new alias (rather than a straight rename) is needed so in-flight PR comments using the old marker aren't orphaned, before changing the constant.

Files

• README.md
• config/examples/README.md, config/examples/TEMPLATES.md
• packages/loopover-engine/src/signals/engine.ts
• src/github/comments.ts (only if a new marker alias is needed)

[linear-code]

JSO-4184