feat: Add SQL Transactions & Concurrency documentation

[dinesh-2047]

Description

PR regenerated
Added [sql-transactions-concurrency.markdown] to explain ACID, isolation levels (READ UNCOMMITTED → SERIALIZABLE), common anomalies (dirty/non-repeatable/phantom reads), and locking strategies (optimistic vs pessimistic) with short examples and best-practice notes.

Fixes #1000

Type of Change

• New feature (e.g., new page, component, or functionality)
• Bug fix (non-breaking change that fixes an issue)
• UI/UX improvement (design, layout, or styling updates)
• Performance optimization (e.g., code splitting, caching)
• Documentation update (README, contribution guidelines, etc.)
• Other (please specify):

Changes Made

file creation - sql-transactions-concurrency.md

Checklist

• My code follows the style guidelines of this project.
• I have tested my changes across major browsers and devices
• My changes do not generate new console warnings or errors .
• I ran npm run build and attached screenshot(s) in this PR.
• This is already assigned Issue to me, not an unassigned issue.

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[github-actions]

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[github-actions]

✅ Synchronized metadata from Issue #1000:

• Labels: enhancement, prioriy:low, level 1, recode, hacktoberfest-accepted
• Milestone: recode:launch 3.0

[github-actions]

✅ Synchronized metadata from Issue #1000:

• Labels: enhancement, prioriy:low, level 1, recode, hacktoberfest-accepted
• Milestone: recode:launch 3.0

[vercel]

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Project	Deployment	Preview	Comments	Updated (UTC)
recode-website	Ready	Preview	Comment	Oct 26, 2025 2:00am