feat(sdk): scaffold @hyperframes/sdk — engine layer (model, RFC 6902 patches, mutate, apply-patches) (#1324)

* feat(sdk): scaffold @hyperframes/sdk — engine layer (model, RFC 6902 patches, mutate, apply-patches)

* fix(sdk): make engine-layer PR self-contained — trim index.ts, guard indexed access

- index.ts no longer exports document/session/history/persist-queue (those
  modules land in the next stacked PR); branch now typechecks standalone
- setOwnText: optional-chain children[i] access (TS2532 under
  noUncheckedIndexedAccess)
- fallow suppressions for buildPatchEvent + adapters/types.ts — consumers
  arrive in #1325

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* fix(sdk): fail loudly on Phase 3b ops; add sdk to root build pipeline

- applyOp throws UnsupportedOpError (code E_UNSUPPORTED_OP) for the 9
  parser-backed ops instead of silently no-opping — callers must never
  believe an animation edit succeeded when nothing was mutated
- validateOp returns false for Phase 3b ops so can() feature-detects
- root package.json build filter now includes @hyperframes/sdk (package is
  dist-only; top-level build previously produced no SDK artifacts).
  publish.yml intentionally NOT updated — sdk stays unpublished until
  Phase 3 completes.

Adversarial-review findings F3 + F4.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* fix(sdk): cross-realm origin sentinel, dual width/height channel, contract docs

Round-2 review (Rames/Miguel) on the engine layer:

- ORIGIN_APPLY_PATCHES: unique symbol → namespaced string
  ('@hyperframes/sdk:applyPatches'). Symbols are realm-local — they don't
  survive postMessage/structured-clone, which T3 embedded hosts may forward
  patch events across. Namespaced string keeps collision risk negligible.
- setCompositionMetadata width/height: runtime treats data-width/data-height
  as a forced override of inline style (init.ts applyCompositionSizing).
  Style is always written; the data-* attr is updated when already present
  so the edit isn't clobbered on load. Absent attrs stay absent — inverses
  stay exact. Mirrored in the patch applier; 3 new tests.
- JsonPatchOp documented as the emit-only RFC 6902 subset
  (add/remove/replace); applier header notes move/copy/test are ignored.
- SdkDocument.html documented as a build-time snapshot (serialize() is the
  live state).
- patches.ts path-grammar comment fixed: timing/{start|end|trackIndex}.

NOT changed (with reasons, see PR reply): moveElement left/top matches
Studio's own inline-style commit convention (sourcePatcher); package version
follows the repo-wide single-version policy.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* fix(sdk): moveElement writes data-x/data-y, not left/top CSS

HF elements use data-x/data-y for positioning (read by htmlParser.ts,
emitted by hyperframes generator). CSS left/top is not the runtime convention.

Adds inverse round-trip test for prior position restore.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* chore: update bun.lock after sdk package registration

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

---------

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

packages/sdk/package.json

@@ -0,0 +1,73 @@
+{
+  "name": "@hyperframes/sdk",
+  "version": "0.6.86",
+  "description": "Headless, framework-neutral HyperFrames composition editing engine",
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/heygen-com/hyperframes",
+    "directory": "packages/sdk"
+  },
+  "files": [
+    "dist",
+    "README.md"
+  ],
+  "type": "module",
+  "sideEffects": false,
+  "exports": {
+    ".": {
+      "import": "./src/index.ts",
+      "types": "./src/index.ts"
+    },
+    "./adapters/memory": {
+      "import": "./src/adapters/memory.ts",
+      "types": "./src/adapters/memory.ts"
+    },
+    "./adapters/fs": {
+      "import": "./src/adapters/fs.ts",
+      "types": "./src/adapters/fs.ts"
+    },
+    "./adapters/headless": {
+      "import": "./src/adapters/headless.ts",
+      "types": "./src/adapters/headless.ts"
+    }
+  },
+  "publishConfig": {
+    "access": "public",
+    "exports": {
+      ".": {
+        "import": "./dist/index.js",
+        "types": "./dist/index.d.ts"
+      },
+      "./adapters/memory": {
+        "import": "./dist/adapters/memory.js",
+        "types": "./dist/adapters/memory.d.ts"
+      },
+      "./adapters/fs": {
+        "import": "./dist/adapters/fs.js",
+        "types": "./dist/adapters/fs.d.ts"
+      },
+      "./adapters/headless": {
+        "import": "./dist/adapters/headless.js",
+        "types": "./dist/adapters/headless.d.ts"
+      }
+    },
+    "main": "./dist/index.js",
+    "types": "./dist/index.d.ts"
+  },
+  "scripts": {
+    "build": "tsc",
+    "test": "vitest run",
+    "test:watch": "vitest",
+    "typecheck": "tsc --noEmit",
+    "typecheck:examples": "tsc --noEmit -p tsconfig.check.json"
+  },
+  "dependencies": {
+    "@hyperframes/core": "workspace:*",
+    "linkedom": "^0.18.12"
+  },
+  "devDependencies": {
+    "@types/node": "^25.0.10",
+    "typescript": "^5.0.0",
+    "vitest": "^3.2.4"
+  }
+}