fix(postgresql): retain current PITR timeline history

[weicao]

What

Exempt recognized PostgreSQL timeline-history archives from the WAL start-boundary comparison during PITR traversal.

Why

A timeline-history basename such as 00000002.history sorts below a timeline-2 WAL segment such as 000000020000000000000001. Applying the segment comparison first silently skipped the required current timeline history while still pulling the segment and returning success.

Tests

• RED (960b4ebf3): Bash 3.2 focused ShellSpec, 18 examples / 1 failure / 2 failed assertions
• GREEN: Bash 3.2 focused ShellSpec, 18 examples / 0 failures
• GREEN: Bash 5.3 full PostgreSQL ShellSpec, 286 examples / 0 failures
• ShellCheck error severity, Bash syntax, and git diff --check
• helm lint addons/postgresql: 1 chart / 0 failures
• helm template: 41 documents / 1,014,451 bytes

[codecov-commenter]

Codecov Report

❌ Patch coverage is 0% with 8 lines in your changes missing coverage. Please review.
✅ Project coverage is 0.00%. Comparing base (30566f4) to head (27005b6).

Files with missing lines	Patch %	Lines
...ns/postgresql/scripts-ut-spec/pitr_restore_spec.sh	0.00%	8 Missing ⚠️

Additional details and impacted files

@@                             Coverage Diff                             @@
##           easton/pg-pitr-restore-history-skip-waldump   #3403   +/-   ##
===========================================================================
  Coverage                                         0.00%   0.00%           
===========================================================================
  Files                                              195     195           
  Lines                                            28389   28397    +8     
===========================================================================
- Misses                                           28389   28397    +8     

☔ View full report in Codecov by Harness.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.