feat(core): add before/after dependency ordering to SystemRegistry

[Exoridus]

Summary

• SystemRegistrationOptions gains before?/after?: readonly System[], additive to the existing numeric order (not a replacement — order/registration sequence still break ties among registrations the dependency graph doesn't relate).
• Per-phase-list (_fixedList/_updateList/_drawList) sort is now a topological sort (Kahn's algorithm) instead of a plain comparator sort, falling back to byte-identical order/sequence behavior when no registration in a given list declares before/after.
• Constraints are scoped per phase: a before/after reference to a system outside the current phase (different phase, or never registered) is a silent no-op there, not an error — the constraint genuinely has nothing to order in that list.
• A cycle throws a clear Error naming the systems involved (via constructor.name), surfaced lazily at the next sort of the affected phase — same dirty-flag-driven timing the registry already used, no new eager-validation path.
• No named SystemSet/label concept — before/after reference concrete System objects directly. The only existing precedent for coordinated ordering in the codebase (SystemOrder enum + PhysicsWorld) is a single-system pattern with no evidence of needing group-based dependencies; label resolution could be added later as a compatible extension (the graph already operates on registration identity), not a redesign.

No public API removal or behavior change for existing order-only callers — internal sort algorithm swap, additive options surface.

Test plan

• New test/core/system-registry.test.ts: baseline order/sequence regression, before pulls ahead regardless of order, after pushes behind regardless of order, tie-break among multiple constrained systems (registration order wins), phase-mismatch silent no-op, cycle throws naming both systems
• TDD: watched all new-behavior tests fail for the right reason before implementing, then pass
• test/core/scene-systems.test.ts + test/core/application-extension-systems.test.ts unmodified, still green
• Full test/core/ directory (63 files, 930 tests) green — no regressions
• pnpm typecheck + pnpm typecheck:type-tests clean (covers the public System/SystemRegistry type contract)
• eslint clean
• pnpm verify:quick (full local pre-push gate) green

[codecov]

Bundle Report

Changes will increase total bundle size by 7.85kB (0.03%) ⬆️. This is within the configured threshold ✅

Detailed changes

Bundle name	Size	Change
exo-esm-esm	875.53kB	875 bytes (0.1%) ⬆️
exo-esm-modules-esm	3.97MB	4.06kB (0.1%) ⬆️
exo-iife-min-Exo-iife	883.28kB	875 bytes (0.1%) ⬆️
exo-full-iife-Exo-iife	2.81MB	2.04kB (0.07%) ⬆️

Affected Assets, Files, and Routes:

view changes for bundle: exo-full-iife-Exo-iife

Assets Changed:

Asset Name	Size Change	Total Size	Change (%)
exo.full.iife.js	2.04kB	2.81MB	0.07%

view changes for bundle: exo-esm-esm

Assets Changed:

Asset Name	Size Change	Total Size	Change (%)
exo.esm.js	875 bytes	875.53kB	0.1%

Files in exo.esm.js:

• ./src/core/SystemRegistry.ts → Total Size: 11.79kB

view changes for bundle: exo-esm-modules-esm

Assets Changed:

Asset Name	Size Change	Total Size	Change (%)
core/SystemRegistry.js	3.16kB	11.93kB	36.03% ⚠️
core/SystemRegistry.d.ts	905 bytes	5.2kB	21.09% ⚠️

Files in core/SystemRegistry.js:

• ./src/core/SystemRegistry.ts → Total Size: 11.79kB

view changes for bundle: exo-iife-min-Exo-iife

Assets Changed:

Asset Name	Size Change	Total Size	Change (%)
exo.iife.min.js	875 bytes	883.28kB	0.1%

Files in exo.iife.min.js:

• ./src/core/SystemRegistry.ts → Total Size: 11.79kB

[codecov]

Codecov Report

❌ Patch coverage is 95.65217% with 2 lines in your changes missing coverage. Please review.
✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
src/core/SystemRegistry.ts	95.65%	2 Missing ⚠️

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