fix(sharding): enable shared TLS for sharding

[leon-ape]

What changed

This is the release-1.1 backport of #10767.

• register the shared sharding TLS transformer in the Cluster reconciliation chain
• honor each active shard template's effective ShardingDefinition.spec.tls.shared
• rewrite only expanded shard Component specs that enable shared TLS
• use fixed internal source keys while preserving optional ComponentDefinition TLS file declarations
• adapt the shared TLS tests to the release-1.1 test layout and CRD API-version compatibility checks

Why

ShardingDefinition.spec.tls.shared is accepted by the API, but the transformer was not registered, so shards received independently generated certificate authorities.

Fixes #10756

Validation

• scripts/codex-go-test.sh ./controllers/apps/cluster -count=1
• scripts/codex-go-test.sh ./controllers/apps/component -count=1

Known follow-ups

• DNS SANs for actual shard service names are not addressed by this backport.
• Cleanup and certificate rotation when leaving shared TLS are intentionally left to a separate lifecycle change.

[apecloud-bot]

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[codecov]

Codecov Report

❌ Patch coverage is 95.28302% with 5 lines in your changes missing coverage. Please review.
✅ Project coverage is 54.33%. Comparing base (b0941eb) to head (c4efe31).

Files with missing lines	Patch %	Lines
...s/apps/cluster/transformer_cluster_sharding_tls.go	94.68%	4 Missing and 1 partial ⚠️

Additional details and impacted files

@@               Coverage Diff               @@
##           release-1.1   #10770      +/-   ##
===============================================
+ Coverage        53.99%   54.33%   +0.34%     
===============================================
  Files              545      545              
  Lines            61305    61364      +59     
===============================================
+ Hits             33103    33345     +242     
+ Misses           25004    24835     -169     
+ Partials          3198     3184      -14     

Flag	Coverage Δ
unittests	54.33% <95.28%> (+0.34%)	⬆️

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[leon-ape]

/approve

[leon-ape]

/approve