chore(deps): upgrade Nondominium to Holochain 0.7 (blocked on hREA)

[Soushi888]

Tracking issue for PR #130 (branch chore/holochain-0.7, draft).

Port is complete and green locally (all zomes build, happ packs, 39/39 Sweettest, UI typechecks). Blocked: requires the companion hREA PR merged first, since Nondominium vendors hREA and both Nondominium and R&O depend on it. Decision (2026-08-15): hREA moves to Holochain 0.7 first, targeted by the v0.1.0 release; Nondominium's upgrade lands after that unblocks.

Open items before merge: independent review of the integrity-zome validation diff, CI fix for the rsync permission error on .claude/skills/holochain, and the 0.7 launcher (launch-happ.mjs never reaches ready in CI). Note: 0.7 changes every DNA hash; conductor data must be cleared, no migration.

[Soushi888]

Sequencing decision (2026-08-15): hREA moves to Holochain 0.7 first

Confirmed by Soushi: hREA must be upgraded to Holochain 0.7 before Nondominium, because both Nondominium and R&O (hAppenings) depend on it. Nondominium vendors hREA at vendor/hrea, so this PR cannot merge until an hREA release on 0.7 exists to vendor.

Target: hREA on 0.7 by the v0.1.0 Nondominium release, at which point the full upgrade can land across the three projects together.

This PR therefore stays parked, and stays out of the v0.1.0 scope as a code change. It is not blocked on review effort; it is blocked on an external dependency with a known owner and a known target.

Prerequisites, current state

• CI rsync permission error on .claude/skills/holochain — fixed on dev in fix(nix): make the materialized .claude/ writable so the skills hook can write #138 (root cause: rsync -a preserved the nix store's read-only mode, so the skills hook could never write into .claude/). This was noise appearing immediately before the launcher failure in this PR's log; the two are unrelated.
• hREA released on Holochain 0.7 (external, prerequisite for vendoring)
• launch-happ.mjs reaching ready under 0.7 in CI (the actual e2e failure here, still open)
• Independent review of the integrity-zome validation diff (never completed per the PR body)

Note on rebase cost

dev has moved considerably since this branch was cut (#137, #128, #138, and NDO Layer 1 when it lands). The 0.7 port rewrites every integrity zome, and Layer 1 adds substantial new integrity code, so this branch should be rebased after Layer 1 merges, so the port is done once against final code with a green Sweettest matrix as the oracle.