chore(marketplace): bump hypermnesia-mcp-viz pin to 3.1.0 (cortex-viz#130)

[cdeust]

Summary

• cdeust/cortex-viz has cut a 3.1.0 release: chore(release): 3.1.0 — align version surfaces, document undocumented commits cortex-viz#130, CI green. Four feat commits (trace streaming refactor(wiki): extract cohesive collaborators from wiki_pages.py #111, wiki graph endpoint META cas-d'école : conformité de Cortex aux best practices du guide d'activation Anthropic #120, static export Exporter OTel pour la télémétrie Cortex (émission OTLP — le dashboard vit hors de Cortex) #122, per-domain static export docs(deployment): corporate proxy / custom CA for model downloads #123) landed after the 3.0.0 breaking-rename release with no further breaking change — SemVer minor, not a re-use of 3.0.0.
• Bumps this repo's hypermnesia-mcp-viz marketplace entry version to 3.1.0 and its source.sha pin.
• This is exactly the step the workflow header on cortex-viz's Release.yaml (and docs/RELEASING.md step 6) calls out as historically skipped: six zetetic-team-subagents releases and two visualization releases reached zero installs because the marketplace pin was never bumped (Cortex bug: marketplace.json pins withhold downstream releases — zetetic-team-subagents stuck 6 releases back, cortex-viz 3, with no signal #179). A green tag build on cortex-viz alone does not ship this plugin to anyone — this pin is the last mile.

Blocked / provisional — do not merge yet

I do not own this repository this session and am not merging here. Also:

• cdeust/cortex-viz#130 is not yet merged (its own repo etiquette requires the owner's go-ahead, not self-merge). The sha in this diff is the current tip of cortex-viz@chore/release-3.1.0 (064e6d1f77bc36e47fd15fbf07969233bda4c32c), not a tagged release commit — no v3.1.0 tag exists yet on cortex-viz.
• Once cortex-viz#130 merges (prior PRs on that repo were squash-merged, so the sha reaching main will likely differ from the one in this diff), the merge commit should be tagged v3.1.0 and the tag pushed to trigger the PyPI/GitHub-release workflow. This PR's sha must be re-pointed to that tag commit before merging — do not merge this PR with the current provisional sha.

Test plan

• .claude-plugin/marketplace.json still valid JSON
• sha re-pointed to the actual v3.1.0 tag commit once cortex-viz#130 merges and is tagged
• This repo's own CI (if any gate exists on marketplace.json) green

Generated with Claude Code

[cdeust]

Closing in favor of #419, which supersedes this PR.

Superseded, not just re-pointed, because #419 does more than fix this pin:

• Fixes the actual root cause this PR's own body named as unresolved — check_marketplace_pins.py never verified a pin's existence, only its staleness, which is exactly why the 3.0.0 pin this PR corrects was never caught by CI in the first place. New PIN_VERSION_UNPUBLISHED/REGISTRY_VERSION_STALE checks close that gap for every pin, not just this one.
• Uses the now-confirmed real values: cortex-viz#130 merged and tagged v3.1.0 at 052e4a40d3e6bddaeb1cec6662e23b451575c481 (not the provisional 064e6d1 PR-head sha this PR carries, which — as this PR's own description already flagged — changed on squash-merge).
• Adds ref: "v3.1.0" to the pin (the marketplace schema supports it; a prior report claiming otherwise was checked here and found wrong) alongside sha.

Thanks for identifying and flagging the dependency correctly in the original description — that note is what let this land cleanly once the real sha was known.

[cdeust]

Closed: superseded by #419.