fix(auth-js): handle absolute URL in basePath

[te2wow]

Fixes #1104

When basePath is set to an absolute URL like http://localhost:8000/api/auth, the URL is built by simple string concatenation (${baseUrl}${basePath}/${path}), resulting in a broken URL like http://localhost:3000http://localhost:8000/api/auth/session. This PR adds normalizeBasePath() in client.ts that splits an absolute URL in basePath into baseUrl and basePath, so that the URL concatenation produces the correct result.

Changes

• client.ts: Add normalizeBasePath() function
• react.tsx: Use normalizeBasePath() in AuthConfigManager.setConfig()
• client.test.ts: Add tests for normalizeBasePath()

The author should do the following, if applicable

• Add tests
• Run tests
• yarn changeset at the top of this repo and push the changeset
• Follow the contribution guide

[changeset-bot]

🦋 Changeset detected

Latest commit: 7c311a6

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

This PR includes changesets to release 1 package

Name	Type
@hono/auth-js	Patch

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 91.71%. Comparing base (96ae310) to head (9aaf63c).
⚠️ Report is 2 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1743      +/-   ##
==========================================
- Coverage   92.68%   91.71%   -0.98%     
==========================================
  Files         112      113       +1     
  Lines        3733     3778      +45     
  Branches      946      954       +8     
==========================================
+ Hits         3460     3465       +5     
- Misses        245      281      +36     
- Partials       28       32       +4     

Flag	Coverage Δ
auth-js	64.34% <100.00%> (-34.23%)	⬇️

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