Only sync skill on prepack, not build

Nothing at build time consumes the package-local skills/ copy now that the
ai command is gone — prepack (which fires on npm pack/publish) is sufficient.

Author: theoephraim

.bumpy/skill-distribution.md

@@ -4,6 +4,6 @@
 
 Streamline agent skill distribution and remove the `bumpy ai` command.
 
-The canonical `add-change` skill now lives at the repo root (`skills/`) as a single source of truth and is synced into the package on `build`/`prepack` (gitignored copy), so it ships version-pinned in the npm tarball and via the Claude Code plugin (`claude plugin install @varlock/bumpy`).
+The canonical `add-change` skill now lives at the repo root (`skills/`) as a single source of truth and is synced into the package on `prepack` (gitignored copy), so it ships version-pinned in the npm tarball and via the Claude Code plugin (`claude plugin install @varlock/bumpy`).
 
 The `bumpy ai setup` command has been removed. Its file-copying targets (`opencode`, `cursor`, `codex`) duplicated the skill into tool-specific directories that drifted from the canonical copy — and had silently been broken in the published package — while the `claude` target was a thin wrapper around `claude plugin install`. Install the skill via the Claude Code plugin, or reference the bundled `SKILL.md` directly from `node_modules/@varlock/bumpy/skills/add-change/SKILL.md`.

packages/bumpy/package.json

@@ -36,7 +36,7 @@
     }
   },
   "scripts": {
-    "build": "bun run scripts/sync-skill.ts && tsdown",
+    "build": "tsdown",
     "prepack": "bun run scripts/sync-skill.ts && cp ../../README.md .",
     "sync-skill": "bun run scripts/sync-skill.ts",
     "check": "bun run tsc --noEmit",

packages/bumpy/scripts/sync-skill.ts

@@ -6,9 +6,10 @@
  *
  * The canonical copy lives at the repo root so a single source of truth feeds
  * both the npm bundle and any future discovery endpoints. This package copy is
- * a generated artifact (gitignored) and is regenerated on every `build` /
- * `prepack` / publish. It is also what the Claude Code plugin manifest
- * (`.claude-plugin/plugin.json`) ships to agents.
+ * a generated artifact (gitignored) and is regenerated on every `prepack` /
+ * publish (run `bun run sync-skill` to refresh it manually). It is also what
+ * the Claude Code plugin manifest (`.claude-plugin/plugin.json`) ships to
+ * agents.
  */
 import { existsSync, rmSync, cpSync } from 'node:fs';
 import { resolve } from 'node:path';