#2156: Add secret placeholders for configuration templates

[Caylipp]

This PR fixes #2156

Implemented changes:

• added generic $[secret:<name>] placeholders for files under templates/conf/
• prompted once per distinct secret name within each template file
• supported repeated and multiple distinct placeholders
• ensured secrets are only written to generated local conf/ files
• preserved source templates and existing local configuration files
• prevented secret values from appearing in production logs
• handled $ and \ in secret values safely

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Testing instructions

Please add conscise, understandable instructions on how a reviewer can test/verify the functionality of your contribution here:

1. Run the focused tests: mvn -pl cli -Dtest=CreateCommandletTest test
2. Run the complete CLI test suite: mvn -pl cli test
3. Optional: Run the ./build-local-dev.sh script and create a test project

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• When running mvn clean test locally all tests pass and build is successful
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[coveralls]

Coverage Report for CI Build 29340292832

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Coverage: 72.278%

Details

• Patch coverage: No coverable lines changed in this PR.

Uncovered Changes

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Coverage Regressions

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Coverage Stats

Relevant Lines:	16751
Covered Lines:	12611
Line Coverage:	75.29%
Relevant Branches:	7468
Covered Branches:	4894
Branch Coverage:	65.53%
Branches in Coverage %:	Yes
Coverage Strength:	3.19 hits per line

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