fix: make persisted edge identities collision-safe

[j6k4m8]

Summary

• generate versioned fixed-length edge identities from unambiguous endpoint encodings
• resolve existing SQL and DynamoDB edges by indexed endpoints so legacy rows remain readable and update in place
• preserve bulk ingestion behavior with bounded endpoint lookup batches
• cover delimiter collisions, long endpoints, and legacy record updates

[codspeed-hq]

Merging this PR will improve performance by ×2.3

⚡ 1 improved benchmark
✅ 16 untouched benchmarks

Performance Changes

	Benchmark	BASE	HEAD	Efficiency
⚡	test_sql_bulk_edge_insertion	198.6 ms	84.9 ms	×2.3

Tip

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_{Comparing fix/collision-safe-edge-identities-75 (1b5112f) with master (fe117e0)}