Add version mismatch warning between standalone binary and local node_modules install

[Copilot]

When users have both a standalone binary (homebrew/curl) and a project-level npm install of varlock at different versions, the CLI silently uses whichever is on PATH, producing confusing errors from version incompatibilities.

Changes

• packages/varlock/src/lib/check-local-version.ts — New checkLocalVersionMismatch() that walks up from cwd looking for node_modules/varlock/package.json and compares its version against the running binary's version
• packages/varlock/src/cli/cli-executable.ts — Calls the check on SEA builds only, skipping --version/--help for clean output
• packages/varlock/src/lib/test/check-local-version.test.ts — 9 tests covering match, mismatch, parent directory traversal, malformed package.json, and missing version field

Behavior

Only triggers when __VARLOCK_SEA_BUILD__ is true and a local install exists with a differing version:

⚠️  Varlock version mismatch detected!
  Standalone binary version: 0.4.0
  Local installed version:   0.6.3
You are running the standalone binary, but a different version of varlock is installed in this project's node_modules.
This can cause unexpected errors. Please update your standalone binary or use the locally installed version instead
(e.g. via npx varlock, pnpm exec varlock, or bunx varlock).

Silently no-ops when: no local install exists, versions match, or package.json is unreadable.

[changeset-bot]

🦋 Changeset detected

Latest commit: d6df257

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 18 packages

Name	Type
varlock	Patch
@varlock/astro-integration	Patch
@varlock/cloudflare-integration	Patch
@varlock/expo-integration	Patch
@varlock/nextjs-integration	Patch
@varlock/vite-integration	Patch
@varlock/1password-plugin	Patch
@varlock/aws-secrets-plugin	Patch
@varlock/azure-key-vault-plugin	Patch
@varlock/bitwarden-plugin	Patch
@varlock/dashlane-plugin	Patch
@varlock/google-secret-manager-plugin	Patch
@varlock/hashicorp-vault-plugin	Patch
@varlock/infisical-plugin	Patch
@varlock/keepass-plugin	Patch
@varlock/pass-plugin	Patch
@varlock/passbolt-plugin	Patch
@varlock/proton-pass-plugin	Patch

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