Chore: add git best-practice standards

[Varnasr]

Summary

• Add .gitattributes (LF line endings, binary markers, lock file merge strategy)
• Add .editorconfig (UTF-8, LF, 2-space indent, Makefile tabs)
• Add .githooks/pre-commit (block secrets, debugger, conflict markers; warn console.log, large files)
• Add .githooks/commit-msg (enforce Add/Fix/Update/Translate/Docs/Refactor/Test/CI/Chore prefix)
• Add .gitmessage (commit template with prefix guide)
• Add .github/CODEOWNERS (@Varnasr as default reviewer)
• Add .github/SECURITY.md (responsible disclosure, hello@impactmojo.in)
• Add .github/dependabot.yml (weekly updates, ecosystem-aware)
• Add .github/pull_request_template.md (type checkboxes, testing checklist)
• Add .github/ISSUE_TEMPLATE/ (bug report, feature request, content issue)
• Update .gitignore (ensure coverage of .env, node_modules, OS files, editor files, build output)
• Update package.json with prepare script (if applicable)

Only missing files were added — existing well-configured files were preserved.

Test plan

• Verify no existing files were overwritten
• Confirm hooks work: git config core.hooksPath .githooks then test a commit
• Check dependabot.yml matches repo ecosystem

https://claude.ai/code/session_0182e6yYaW76Z7WNaEb1j1K3