[Exeloo]

What does this PR do?

Closes #289
Refs #291 (breakout now gets CLI 3.0.1 from the engine's e2e game, but NANOFORGE_CLI is still not linked into it)

Example games now live in the examples repository (NanoForge-dev/examples feat/centralize-games). Only test games stay here, and the editor no longer reads the engine's removed example/ folder.

• examples/breakout → plugins/scene/test/fixtures/breakout (frozen: the scene goldens and scene.spec.ts pin its text). examples/ keeps only counter-plugin.
• packages/server-core/test/fixtures/game: the engine's pong-network at 3.0.0, frozen, as the e2e game. The e2e prep and setup-check take node_modules from <engine>/e2e/game; the engine pin moves to ed8c7e0 (engine 3.0.0). Fixtures on engine ^3.0.0 and CLI/config ^3.0.1.
• pnpm examples (scripts/examples.mjs): copies chosen games from a local examples checkout (--from, NANOFORGE_EXAMPLES, ../examples, or asked for; @inquirer/prompts checkbox, or --games/--all) into the gitignored .examples/, installs each copy, optionally links a local engine (--engine). pnpm example <name> opens a copy in the built editor (port 4800).
• apps/editor/test/examples/editor-native.spec.ts: runs the ECS and scene analyzers over every copied game and fails on what the editor can't model; skipped when .examples/ is empty.
• Docs: README, AGENTS.md, examples/README.md, docs/docs/editor/scenes.mdx (links games/breakout).

How do you test this PR?

pnpm examples --from ../examples --games input-keyboard,breakout,raid-survival
pnpm example breakout

Run on HEAD: pnpm build 17/17, pnpm lint 29/29, pnpm typecheck 41/41, CHROME=… pnpm test (editor-native spec 4/4 on breakout, input-keyboard, network, raid-survival; it fails on a seeded file with no item), full e2e "109 passed" with E2E_REQUIRE_ENGINE=1, runtime/scene/tutorial/console 13 passed on pin ed8c7e0. pnpm install --frozen-lockfile passes. Examples checkout git status unchanged after copying.

Merge danger

Two-way door: tooling, fixtures and docs; no published package or API change. apps/editor deploys on merge (ADR 0006) but no runtime code changed. Merge after NanoForge-dev/examples feat/centralize-games (the docs and pnpm examples expect its layout), together with NanoForge-dev/Engine feat/examples-games.

Follow-up issues

• Docs still name the removed engine/example/pong-network #296 (docs still name engine/example/pong-network)
• pnpm examples follows symlinks out of a game and can replace .examples/.data #297 (pnpm examples: symlinks and .examples/.data)
• One copy tool for example games instead of one in the editor and one in the engine #298 (one copy tool for the editor and the engine)

Quality gate

Check	Result	Notes
Docs	Updated	1829e18 plus the producer's docs commits
Correctness	Pass	fix 0610656 (checklist starts unticked, no cache for test:coverage, release-age exclusions restored)
Performance	N/A (tooling, tests and docs only)
Accessibility	Pass	Minor only (link text, path prompt error)
Security	Pass	Minor only (symlinks, .data name)
Style	Pass	lint: pass; questions on the spec's plugin src imports and the new @inquirer/prompts dependency