fix(sync): stats unavailable hotfix (v3.5.1)

[night-slayer18]

Summary

Fixes the leetcode sync command always showing Stats unavailable in commit bodies.

Root Causes

Two independent bugs, both confirmed via live API probe:

1. Missing credential loading — syncCommand() called getSubmissionList() before loading stored session credentials onto the HTTP client. Git auth (SSH/PAT) is independent of the LeetCode session, so the command could push to GitHub while unauthenticated against the LeetCode API.

2. Schema type mismatch — SubmissionDetailsSchema declared runtime and memory as string, but the API returns them as number (raw ms / bytes). Zod rejected every response, triggering the catch block for every user on every problem.

Changes

• src/commands/sync.ts — call setupClientIfLoggedIn() at entry
• src/schemas/api.ts — runtime/memory accept number | string, lang nullable
• src/types.ts — SubmissionDetails interface updated to match
• src/commands/submissions.ts — null guard for details.lang
• src/__tests__/commands/sync.test.ts — 5 new regression tests (20 total)
• release.mjs — new release prep script
• docs/releases.md — v3.5.1 changelog entry
• package.json / src/index.ts — version bumped to 3.5.1

Testing

All 350 tests pass. Verified live against LeetCode API with authenticated session.

[github-actions]

Thanks for the PR, @night-slayer18! 🎉

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• Documentation updated if needed
• PR targets the dev branch (not main)

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