fix: add .js extensions to relative imports for ESM compatibility

[tnkshuuhei]

Summary

• Add explicit .js file extensions to all relative import/export statements in source TypeScript files
• Update bundle-content.ts generated code templates to include .js extensions
• This ensures the compiled dist/ output works correctly as an ES module package in Node.js environments (Next.js, Mastra)

Problem

The TypeScript compiler (tsc) preserves bare module specifiers (e.g., from "./types") verbatim in compiled output. Since this package uses "type": "module", Node.js ESM resolution requires explicit file extensions (from "./types.js"). Without them, module resolution fails in strict ESM environments.

Currently, the muse project works around this with a patch file (patches/@beaconlabs-io%2Fevidence@1.1.3.patch). This fix addresses the root cause so the patch can be removed.

Changes

File	Change
src/index.ts	./types → ./types.js, ./content → ./content/index.js
src/content/index.ts	../types → ../types.js, ./evidence → ./evidence.js, ./deployments → ./deployments.js
scripts/bundle-content.ts	Generated import templates: ../types → ../types.js (2 places)

Test plan

• bun run build completes successfully
• dist/index.js contains from "./types.js" and from "./content/index.js"
• dist/content/index.js contains .js extensions on all relative imports
• After publish, remove patch in muse/ and verify bun dev / bun run build work

🤖 Generated with Claude Code