feat(sdk): Experimental zipstream lib, add segment-based streaming ZIP writer, ZIP64 modes

[elizabethhealy]

Proposed Changes

• add a new zipstream lib with segment-based streaming ZIP writer, ZIP64 modes
• package is EXPERIMENTAL (and internal)

• Introduce SegmentWriter for deterministic, out-of-order segment writing and true streaming output.
• Add CRC32 combine (crc32combine) to compute payload CRC without buffering entire payload.
• Implement zip primitives (headers, central directory, EOCD) with ZIP64 mode control (Auto/Always/Never) and signed data descriptors.
• Replace legacy tdf3 writer; remove old writer tests and reader/writer harness.
• Update reader tests and add ZIP64 mode tests and benchmarks.
• Integrate new writer into SDK TDF creation; track total size from streamed segments + finalize bytes.
• Adjust TDF tests’ expected sizes and tolerances to match new ZIP layout.

Notes:
Small archives may differ by ~40–60 bytes vs. legacy due to conditional ZIP64 extras and data descriptor signature; output remains ZIP-spec compliant.

Checklist

• I have added or updated unit tests
• I have added or updated integration tests (if appropriate)
• I have added or updated documentation

Testing Instructions

[github-actions]

Benchmark results, click to expand

Benchmark authorization.GetDecisions Results:

Metric	Value
Approved Decision Requests	1000
Denied Decision Requests	0
Total Time	152.673686ms

Benchmark authorization.v2.GetMultiResourceDecision Results:

Metric	Value
Approved Decision Requests	1000
Denied Decision Requests	0
Total Time	83.70133ms

Standard Benchmark Metrics Skipped or Failed

Bulk Benchmark Results

Metric	Value
Total Decrypts	100
Successful Decrypts	100
Failed Decrypts	0
Total Time	378.386651ms
Throughput	264.28 requests/second

TDF3 Benchmark Results:

Metric	Value
Total Requests	5000
Successful Requests	5000
Failed Requests	0
Concurrent Requests	50
Total Time	39.515821096s
Average Latency	393.08261ms
Throughput	126.53 requests/second

NANOTDF Benchmark Results:

Metric	Value
Total Requests	5000
Successful Requests	5000
Failed Requests	0
Concurrent Requests	50
Total Time	27.126276156s
Average Latency	270.241489ms
Throughput	184.32 requests/second

[github-actions]

Benchmark results, click to expand

Benchmark authorization.GetDecisions Results:

Metric	Value
Approved Decision Requests	1000
Denied Decision Requests	0
Total Time	174.998832ms

Benchmark authorization.v2.GetMultiResourceDecision Results:

Metric	Value
Approved Decision Requests	1000
Denied Decision Requests	0
Total Time	103.192608ms

Standard Benchmark Metrics Skipped or Failed

Bulk Benchmark Results

Metric	Value
Total Decrypts	100
Successful Decrypts	100
Failed Decrypts	0
Total Time	366.168956ms
Throughput	273.10 requests/second

TDF3 Benchmark Results:

Metric	Value
Total Requests	5000
Successful Requests	5000
Failed Requests	0
Concurrent Requests	50
Total Time	37.704664844s
Average Latency	375.142185ms
Throughput	132.61 requests/second

NANOTDF Benchmark Results:

Metric	Value
Total Requests	5000
Successful Requests	5000
Failed Requests	0
Concurrent Requests	50
Total Time	26.041170291s
Average Latency	259.466628ms
Throughput	192.00 requests/second

[github-actions]

Benchmark results, click to expand

Benchmark authorization.GetDecisions Results:

Metric	Value
Approved Decision Requests	1000
Denied Decision Requests	0
Total Time	177.221142ms

Benchmark authorization.v2.GetMultiResourceDecision Results:

Metric	Value
Approved Decision Requests	1000
Denied Decision Requests	0
Total Time	100.541226ms

Standard Benchmark Metrics Skipped or Failed

Bulk Benchmark Results

Metric	Value
Total Decrypts	100
Successful Decrypts	100
Failed Decrypts	0
Total Time	358.474408ms
Throughput	278.96 requests/second

TDF3 Benchmark Results:

Metric	Value
Total Requests	5000
Successful Requests	5000
Failed Requests	0
Concurrent Requests	50
Total Time	38.731321697s
Average Latency	384.042926ms
Throughput	129.09 requests/second

NANOTDF Benchmark Results:

Metric	Value
Total Requests	5000
Successful Requests	5000
Failed Requests	0
Concurrent Requests	50
Total Time	26.645946822s
Average Latency	265.554456ms
Throughput	187.65 requests/second

[github-actions]

Benchmark results, click to expand

Benchmark authorization.GetDecisions Results:

Metric	Value
Approved Decision Requests	1000
Denied Decision Requests	0
Total Time	183.984742ms

Benchmark authorization.v2.GetMultiResourceDecision Results:

Metric	Value
Approved Decision Requests	1000
Denied Decision Requests	0
Total Time	100.866955ms

Standard Benchmark Metrics Skipped or Failed

Bulk Benchmark Results

Metric	Value
Total Decrypts	100
Successful Decrypts	100
Failed Decrypts	0
Total Time	354.865706ms
Throughput	281.80 requests/second

TDF3 Benchmark Results:

Metric	Value
Total Requests	5000
Successful Requests	5000
Failed Requests	0
Concurrent Requests	50
Total Time	38.546610458s
Average Latency	382.828939ms
Throughput	129.71 requests/second

NANOTDF Benchmark Results:

Metric	Value
Total Requests	5000
Successful Requests	5000
Failed Requests	0
Concurrent Requests	50
Total Time	26.321777803s
Average Latency	262.366445ms
Throughput	189.96 requests/second

[github-actions]

Benchmark results, click to expand

Benchmark authorization.GetDecisions Results:

Metric	Value
Approved Decision Requests	1000
Denied Decision Requests	0
Total Time	176.393035ms

Benchmark authorization.v2.GetMultiResourceDecision Results:

Metric	Value
Approved Decision Requests	1000
Denied Decision Requests	0
Total Time	98.659458ms

Standard Benchmark Metrics Skipped or Failed

Bulk Benchmark Results

Metric	Value
Total Decrypts	100
Successful Decrypts	100
Failed Decrypts	0
Total Time	356.664244ms
Throughput	280.38 requests/second

TDF3 Benchmark Results:

Metric	Value
Total Requests	5000
Successful Requests	5000
Failed Requests	0
Concurrent Requests	50
Total Time	38.176108322s
Average Latency	380.218058ms
Throughput	130.97 requests/second

NANOTDF Benchmark Results:

Metric	Value
Total Requests	5000
Successful Requests	5000
Failed Requests	0
Concurrent Requests	50
Total Time	27.106137389s
Average Latency	270.043573ms
Throughput	184.46 requests/second