feat: add shared KMP S3 client for Cells transfers [WPB-26729]

[MohamadJaara]

https://wearezeta.atlassian.net/browse/WPB-26729

Adds a shared internal S3-compatible client for Cells object transfers and uses it across Apple, JVM, and Android.

Changes

• Add internal KMP S3-compatible client for Cells transfers
  • object download
  • regular upload
  • multipart upload
  • complete multipart upload
  • pre-signed GET URLs
• Add SigV4 signing, S3 URL canonicalization, and Ktor/Okio streaming helpers
• Replace Apple no-op Cells upload/download/pre-sign implementations with real behavior
• Wire JVM/Android to the same shared CellsS3Client
• Remove the old JVM/Android AWS SDK S3 dependency and AWS-specific helper classes
• Add focused tests for SigV4 signing, URL construction, upload request signing, and pre-signed URLs

Notes

The implementation keeps S3-specific behavior internal to :domain:cells behind CellsAwsClient. It avoids pulling in the AWS Swift SDK and removes the previous JVM/Android AWS SDK path, so all supported targets now exercise the same limited S3-compatible implementation.

[github-actions]

Test Results

0 tests   - 5 853   0 ✅  - 5 710   0s ⏱️ - 4m 29s
0 suites  -   885   0 💤  -   143 
0 files    -   885   0 ❌ ±    0 

Results for commit 4490c37. ± Comparison against base commit 5a1da91.

♻️ This comment has been updated with latest results.

[codecov-commenter]

Codecov Report

❌ Patch coverage is 85.55046% with 63 lines in your changes missing coverage. Please review.
✅ Project coverage is 61.55%. Comparing base (5a1da91) to head (4490c37).

Files with missing lines	Patch %	Lines
...kotlin/com/wire/kalium/cells/data/CellsS3Client.kt	89.92%	17 Missing and 11 partials ⚠️
...in/com/wire/kalium/cells/data/CellsAwsClientJvm.kt	0.00%	14 Missing ⚠️
...otlin/com/wire/kalium/cells/data/AwsSigV4Signer.kt	90.90%	7 Missing ⚠️
.../kotlin/com/wire/kalium/cells/data/KtorOkioCopy.kt	71.42%	5 Missing and 1 partial ⚠️
...tlin/com/wire/kalium/cells/data/S3UploadChannel.kt	44.44%	5 Missing ⚠️
.../kotlin/com/wire/kalium/cells/data/S3UrlBuilder.kt	91.89%	2 Missing and 1 partial ⚠️

Additional details and impacted files

@@              Coverage Diff              @@
##             develop    #4262      +/-   ##
=============================================
+ Coverage      61.24%   61.55%   +0.31%     
- Complexity      4012     4046      +34     
=============================================
  Files           2161     2163       +2     
  Lines          69390    69675     +285     
  Branches        6886     6907      +21     
=============================================
+ Hits           42498    42891     +393     
+ Misses         24129    24007     -122     
- Partials        2763     2777      +14     

Files with missing lines	Coverage Δ
.../kotlin/com/wire/kalium/cells/data/S3UrlBuilder.kt	91.89% <91.89%> (ø)
...tlin/com/wire/kalium/cells/data/S3UploadChannel.kt	44.44% <44.44%> (ø)
.../kotlin/com/wire/kalium/cells/data/KtorOkioCopy.kt	71.42% <71.42%> (ø)
...otlin/com/wire/kalium/cells/data/AwsSigV4Signer.kt	90.90% <90.90%> (ø)
...in/com/wire/kalium/cells/data/CellsAwsClientJvm.kt	0.00% <0.00%> (ø)
...kotlin/com/wire/kalium/cells/data/CellsS3Client.kt	89.92% <89.92%> (ø)

... and 2 files with indirect coverage changes

---

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[github-actions]

Bencher Report

Branch	${GITHUB_HEAD_REF}
Testbed	ubuntu-latest

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Benchmark	Latency	microseconds (µs)
com.wire.kalium.benchmarks.logic.CoreLogicBenchmark.createObjectInFiles	📈 view plot ⚠️ NO THRESHOLD	889.49 µs
com.wire.kalium.benchmarks.logic.CoreLogicBenchmark.createObjectInMemory	📈 view plot ⚠️ NO THRESHOLD	328,241.24 µs
com.wire.kalium.benchmarks.persistence.MessageReadBenchmark.inboxPagingDeepPageBenchmark	📈 view plot ⚠️ NO THRESHOLD	133,047.87 µs
com.wire.kalium.benchmarks.persistence.MessageReadBenchmark.inboxPagingFirstPageBenchmark	📈 view plot ⚠️ NO THRESHOLD	127,569.05 µs
com.wire.kalium.benchmarks.persistence.MessageReadBenchmark.localMarkAsReadBenchmark	📈 view plot ⚠️ NO THRESHOLD	3,687.17 µs
com.wire.kalium.benchmarks.persistence.MessageReadBenchmark.messagePagingDeepPageBenchmark	📈 view plot ⚠️ NO THRESHOLD	36,936.52 µs
com.wire.kalium.benchmarks.persistence.MessageReadBenchmark.messagePagingFirstPageBenchmark	📈 view plot ⚠️ NO THRESHOLD	21,821.00 µs
com.wire.kalium.benchmarks.persistence.MessagesNoPragmaTuneBenchmark.messageInsertionBenchmark	📈 view plot ⚠️ NO THRESHOLD	1,254,594.19 µs
com.wire.kalium.benchmarks.persistence.MessagesNoPragmaTuneBenchmark.queryMessagesBenchmark	📈 view plot ⚠️ NO THRESHOLD	20,156.12 µs

🐰 View full continuous benchmarking report in Bencher

[MohamadJaara]

@claude review

[github-actions]

🤖 Beep boop! Claude is putting on their reading glasses and diving into your code...

⏳ This comment will be updated with the review results once I'm done pondering the mysteries of your implementation.

In the meantime, feel free to grab a coffee ☕ - reviewing code is serious business!

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud