fix: decouple gram/WASM from @relateby/pattern, add browser export condition

[akollegger]

Summary

Closes #87.

Bundlers (Turbopack, webpack) were pulling in gram.js and its WASM+fs dependencies even when Gram was never imported, because @relateby/pattern barrel-exported Gram. The package split already existed in name — @relateby/gram was a hollow re-export shell. This PR completes it.

What changed

@relateby/gram now owns the full implementation:

• gram.ts, wasm-types.d.ts, wasm/, wasm-node/ moved here from @relateby/pattern
• New gram-browser.ts + index-browser.ts: a browser-only WASM loader with zero Node.js built-in imports (module, url, path), selected via the "browser" export condition
• package.json: wasm build scripts and @types/node moved here; "browser" export condition added
• gram-errors and gram-parity tests migrated from pattern

@relateby/pattern is now pure TypeScript:

• export { Gram } removed from src/index.ts
• gram.ts, wasm-types.d.ts deleted; wasm/ and wasm-node/ dirs removed
• Build simplified to tsc only — no wasm-pack steps
• Public-API tests updated to reflect removed Gram export

Why two separate fixes

1. Moving Gram to @relateby/gram solves the reported issue — consumers of @relateby/pattern can't accidentally pull in WASM because there's nothing to pull.
2. The browser export condition on @relateby/gram solves the follow-on issue — consumers who do import Gram from @relateby/gram and bundle for a browser target get an entry point with no import("module")/import("url")/import("path") calls, which is what Turbopack and similar bundlers require.

Breaking change

Consumers importing Gram from @relateby/pattern must update to:

import { Gram } from "@relateby/gram"

Test plan

• @relateby/pattern tests: 85 passed (all gram tests removed/migrated)
• @relateby/gram tests: 23 passed (gram-errors, gram-parity, public-api)
• @relateby/pattern public-API type check: clean
• dist/gram-browser.js confirmed to contain no Node.js built-in imports

[Copilot]

Pull request overview

This PR completes the separation of the Gram/WASM implementation from @relateby/pattern into @relateby/gram, and adds a "browser" export condition so browser bundlers can resolve @relateby/gram without pulling in Node.js built-ins.

Changes:

• Remove Gram from @relateby/pattern’s public barrel exports and simplify its build to TypeScript-only (tsc).
• Move Gram implementation/tests into @relateby/gram, add index-browser.ts + gram-browser.ts, and wire them via the "browser" export condition.
• Update interop/tests to import Gram from the new package location.

Reviewed changes

Copilot reviewed 14 out of 16 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
typescript/packages/pattern/tests/public-api/export_inventory.test.ts	Updates expected @relateby/pattern export surface (removes Gram).
typescript/packages/pattern/tests/public-api/consumer.ts	Removes Gram usage from pattern public API consumer test.
typescript/packages/pattern/tests/pattern.test.ts	Removes Gram/WASM integration tests from @relateby/pattern.
typescript/packages/pattern/src/index.ts	Stops re-exporting Gram from @relateby/pattern.
typescript/packages/pattern/package.json	Removes wasm build steps; build becomes tsc-only.
typescript/packages/gram/tsconfig.json	Adds Node types + excludes generated wasm dirs from TS compilation.
typescript/packages/gram/tests/gram-parity.test.ts	Migrates gram parity test; imports shared errors from @relateby/pattern.
typescript/packages/gram/tests/gram-errors.test.ts	Migrates gram error tests; imports core types from @relateby/pattern.
typescript/packages/gram/src/wasm-types.d.ts	Adds ambient typings for generated wasm modules (currently mismatched to actual exports).
typescript/packages/gram/src/index.ts	Makes @relateby/gram the primary Gram entry point and adds an explicit init().
typescript/packages/gram/src/index-browser.ts	New browser-conditioned entrypoint exporting Gram from the browser loader.
typescript/packages/gram/src/gram.ts	Node+Vite-capable WASM loader and Promise-based Gram API surface.
typescript/packages/gram/src/gram-browser.ts	New browser/bundler-friendly WASM loader with no Node built-in imports.
typescript/packages/gram/package.json	Adds "browser" export condition and moves wasm build+assets scripts to @relateby/gram.
tests/interop/ts_interop.mjs	Points TS interop test at @relateby/gram’s built Gram module.
package-lock.json	Lockfile updates for moved scripts/deps (e.g., @types/node).