refactor: extract @hyperframes/parsers from core (#1755)

## Summary

Extracts the GSAP parser/writer suite, HTML parser, hf-ids, spring-ease, and the shared composition data types out of `@hyperframes/core/src/parsers/` into a new, independently-publishable **`@hyperframes/parsers`** package.

This is the foundation of the [#1749](https://github.com/heygen-com/hyperframes/issues/1749) effort: make HyperFrames' parsing/linting/validation usable as plain libraries in a Node app, without shelling out to the CLI. Parsers is the standalone base every other extracted package builds on.

**Part 1 of 3** — splits #1754 into independently-reviewable pieces. Parts 2 (lint) and 3 (studio-server) stack on this branch.

## What moves

| | |
|---|---|
| Source moved out of core | **~9,900 LOC** (`src/parsers/` → `packages/parsers/src/`) |
| Total lines removed from core (incl. tests + goldens) | ~19,600 |
| Files relocated | 39 |
| Tests carried over | **660 passing** (5 skipped, 3 todo) |

The big movers: `gsapParser` / `gsapParserAcorn` (the recast + acorn dual parsers), `gsapWriterAcorn`, `gsapSerialize`, `gsapUnroll`, `htmlParser`, `hfIds`, `springEase`, `stableIds`, plus the `__goldens__` corpus.

## Bundle footprint of the new package

| Artifact | Size |
|---|---|
| `dist/` (unpacked) | 1.7 MB |
| npm tarball (packed) | 409 KB |
| `dist/index.js` | 90 KB (**~21 KB gzipped**) |
| Heaviest entries | `gsapWriterAcorn.js` 93 KB · `gsapParser.js` 91 KB |

Most of the weight is the GSAP AST machinery (recast/babel/acorn). It's tree-shakeable via subpath entries (`@hyperframes/parsers/hf-ids`, `/gsap-constants`, etc.) so a consumer that only needs `hf-ids` (2 KB) doesn't pull the parsers.

## How `@hyperframes/core` changes

The interesting part: **core sheds its entire AST toolchain.**

| core `dependencies` | before | after |
|---|---|---|
| count | 9 | 6 |
| removed | — | `@babel/parser`, `acorn`, `acorn-walk`, `magic-string`, `recast` |
| added | — | `@hyperframes/parsers`, `linkedom` |

Before this PR, importing `@hyperframes/core` at all dragged in babel + recast + acorn just to construct types. Now those live behind `@hyperframes/parsers`, and a consumer that only wants core's runtime/compiler types never resolves the parser stack. Core keeps thin `@deprecated` re-export stubs at the old subpaths (`@hyperframes/core/gsap-parser`, `/gsap-constants`, …) so nothing downstream breaks.

## Design notes

- **`"bun"` export condition before `"node"`** in every package export. Bun resolves the TypeScript source directly (no pre-built `dist/`), while Node/tsx/Docker contexts fall through to `"node"` → `dist/`. This keeps the dev loop zero-build while published artifacts stay Node-consumable.
- `@hyperframes/parsers` is **standalone** — zero `@hyperframes/*` dependencies — so it can be the base of the stack.

## Test plan

- [x] `bun run --filter @hyperframes/parsers test` — 660 tests pass
- [x] `bun run --filter @hyperframes/sdk test` — 382 tests pass
- [x] `bun run build` — full monorepo build succeeds
- [x] Fallow audit passes on CI

.github/workflows/ci.yml

@@ -227,6 +227,8 @@ jobs:
       - uses: ./.github/actions/prepare-ffmpeg-bin
       - run: bun install --frozen-lockfile
       - run: bun run test:scripts
+      - run: bun run --filter '@hyperframes/parsers' build
+      - run: bun run --cwd packages/core build
       - run: bun run --cwd packages/core build:hyperframes-runtime
       - run: bun run --filter '!@hyperframes/producer' test
 
@@ -315,6 +317,10 @@ jobs:
       - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4
       - uses: oven-sh/setup-bun@0c5077e51419868618aeaa5fe8019c62421857d6 # v2
       - run: bun install --frozen-lockfile
+      # Build workspace deps so the sdk's @hyperframes/parsers + core subpath
+      # imports resolve via the "node" export condition (dist) under vitest.
+      - run: bun run --filter '@hyperframes/parsers' build
+      - run: bun run --cwd packages/core build
       - run: bun run --filter @hyperframes/sdk test
 
   test-runtime-contract:
@@ -351,6 +357,10 @@ jobs:
           node-version: 22
       - uses: ./.github/actions/prepare-ffmpeg-bin
       - run: bun install --frozen-lockfile
+      # Build workspace deps so the studio vite.config.ts (loaded by Node) can
+      # resolve @hyperframes/core via the "node" export condition (dist).
+      - run: bun run --filter '@hyperframes/parsers' build
+      - run: bun run --cwd packages/core build
       - run: bun run --cwd packages/core build:hyperframes-runtime
       - name: Start studio and check for runtime errors
         run: |

.github/workflows/preview-regression.yml

@@ -36,6 +36,7 @@ jobs:
           filters: |
             preview:
               - "packages/core/**"
+              - "packages/parsers/**"
               - "packages/player/**"
               - "packages/studio/**"
               - "packages/cli/**"
@@ -73,6 +74,11 @@ jobs:
 
       - run: bun install --frozen-lockfile
 
+      - name: Build workspace packages (required for vite config loading)
+        run: |
+          bun run --filter '@hyperframes/parsers' build
+          bun run --cwd packages/core build
+
       - name: Run Studio preview routing regression
         run: |
           bun run --cwd packages/studio test -- vite.thumbnail.test.ts src/utils/projectRouting.test.ts src/utils/frameCapture.test.ts

.github/workflows/publish.yml

@@ -124,6 +124,7 @@ jobs:
             fi
           }
 
+          publish_pkg "@hyperframes/parsers" "@hyperframes/parsers"
           publish_pkg "@hyperframes/core" "@hyperframes/core"
           publish_pkg "@hyperframes/sdk" "@hyperframes/sdk"
           publish_pkg "@hyperframes/engine" "@hyperframes/engine"