feat: use raw SQLCipher keys for new user databases [WPB-27001]

[MohamadJaara]

Summary

• preserve V1 password-derived SQLCipher keys for existing user databases
• generate fresh 32-byte V2 keys for newly created user databases
• encode V2 keys using SQLCipher's raw-key x'<hex>' representation, avoiding PBKDF2 on database open
• version key material through distinct aliases and cover selection/formatting with unit and Android device tests

Stack

1. Durable database-key storage infrastructure
2. This PR: raw SQLCipher V2 keys for new user databases
3. Eager global database migration to a fresh raw V2 key

This PR intentionally does not migrate existing user databases.

[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

[github-actions]

Test Results

0 tests  ±0   0 ✅ ±0   0s ⏱️ ±0s
0 suites ±0   0 💤 ±0 
0 files   ±0   0 ❌ ±0 

Results for commit b89575d. ± Comparison against base commit a3a70b2.

♻️ This comment has been updated with latest results.

[codecov-commenter]

Codecov Report

❌ Patch coverage is 74.41860% with 11 lines in your changes missing coverage. Please review.
⚠️ Please upload report for BASE (mo/sqlcipher-durable-key-storage@a3a70b2). Learn more about missing BASE report.

Files with missing lines	Patch %	Lines
...otlin/com/wire/kalium/logic/util/SecurityHelper.kt	74.41%	6 Missing and 5 partials ⚠️

Additional details and impacted files

@@                         Coverage Diff                         @@
##             mo/sqlcipher-durable-key-storage    #4282   +/-   ##
===================================================================
  Coverage                                    ?   61.24%           
  Complexity                                  ?     4012           
===================================================================
  Files                                       ?     2161           
  Lines                                       ?    69437           
  Branches                                    ?     6895           
===================================================================
  Hits                                        ?    42530           
  Misses                                      ?    24139           
  Partials                                    ?     2768           

Files with missing lines	Coverage Δ
...otlin/com/wire/kalium/logic/util/SecurityHelper.kt	85.00% <74.41%> (ø)

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