chore(env): add Cursor Cloud Agent development environment

[Looted]

What

Adds a repo-managed Cursor Cloud Agent development environment so agents boot into a ready-to-work Kibi checkout.

• .cursor/environment.json — uses the default base image and wires the install phase.
• .cursor/install.sh — idempotent bootstrap that installs the two toolchain prerequisites missing from the default image and then installs workspace dependencies:
  • SWI-Prolog (>= 9, from the official ppa:swi-prolog/stable, matching CI) + bubblewrap
  • Bun pinned to 1.3.10 (the version CI uses), symlinked onto PATH
  • bun install --frozen-lockfile for the workspace (and .opencode when it declares a manifest)

The default base image already provides Node.js, git, python3, curl, and passwordless sudo, so only Prolog and Bun need to be added. The script is guarded (command -v) so re-runs are no-ops.

Why

The repo requires SWI-Prolog and Bun (see CONTRIBUTING.md and .github/workflows/ci.yml), neither of which ships in the default Cloud Agent image. Without this, agents can't bun install, build, run tests, or exercise the Prolog-backed kibi CLI.

Validation

Validated on this VM and in a fresh Cloud Agent booted from a draft build of this branch (build bld-20260818-1d724271-cc8f-463b-9ddf-d625f657b91b, status SUCCEEDED).

Check	Result
install.sh (SWI-Prolog + Bun + deps)	Exit 0; SWI-Prolog 10.0.2, Bun 1.3.10 installed
bun install --frozen-lockfile idempotence	"no changes" on re-run
bun run typecheck (full matrix, 15 projects)	0 errors
bun run build (all packages)	Exit 0
bun run test:unit	1809 pass (see note below)
kibi sync on the real repo KB	900+ entities, 7729 relationships via the Prolog engine
kibi check (structural + contradiction rules)	0 violations
kibi doctor (fresh agent)	All checks pass, SWI-Prolog detected
Fresh Cloud Agent from build	bun 1.3.10 / node v22.14.0 / swipl 10.0.2; build + CLI + tests pass

Note on unit tests

The full test:unit orchestrator reported 3 failures, all environment artifacts rather than repo or environment-config defects (each passes in isolation / in CI):

• kibi init > init --github scaffolds the documented report workflow — the Cloud Agent injects a ~/.gitconfig insteadOf rewrite that turns https://github.com/... into https://x-access-token:<token>@github.com/... (required for git push). The test's remote-URL parser doesn't expect the embedded token, so the badge isn't written. This does not affect real usage.
• kibi migrate > reports missing config file... and kibi branch lifecycle > rejects cross-branch copying... — beforeEach/afterEach timeouts under the full parallel orchestrator on a cold VM (SWI-Prolog subprocess cold-start). Both pass cleanly when run in isolation.

Notes

• biome check reports pre-existing style errors on develop; it is not a CI gate in ci.yml, so it is left untouched (out of scope for environment setup).