Add more built-in procedures

[habedi]

• Added more built-in procedures (by porting implementations from Graphina).
• Fixed a few bugs in the Windows ARM64 build workflow.
• Revised and polished project documentation (including examples, AGENTS.md files, MkDocs, etc.).
• Fixed a few linter warnings and a lot of bugs.
• Revised and improved the playground app.

[codecov]

Codecov Report

❌ Patch coverage is 98.29317% with 17 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
crates/issundb-core/src/graph/kernels/analytics.rs	97.78%	14 Missing ⚠️
crates/issundb-cypher/src/exec/expr.rs	97.40%	2 Missing ⚠️
crates/issundb-vector/src/index.rs	97.43%	1 Missing ⚠️

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