[MNG-8425] Fix mvnenc init saving invalid master source configuration

[Hiteshsai007]

[MNG-8425] Fix mvnenc init saving invalid master source configuration

Fixes #10202

Description

This PR fixes MNG-8425 (#10202) where mvn --enc init generates an invalid settings-security4.xml, causing mvn --enc encrypt to fail with "Maven Encryption is not configured."

Root Cause

When the encryption wizard prompts the user to customize an editable value, the template is presented as env:$VARIABLE_NAME. The user is expected to replace only the $VARIABLE_NAME portion (e.g., typing MVN_PASSWORD), but the Init goal saves the raw user input directly — resulting in <value>MVN_PASSWORD</value> instead of the correct <value>env:MVN_PASSWORD</value>.

The MasterDispatcher in plexus-sec-dispatcher then fails validation because no MasterSource recognizes a config string without its required prefix (env:, sys-property:, etc.), producing the error: Configured Source configuration not handled.

Fix

In Init.java, after the user provides their input for an editable field, the code now:

1. Extracts the prefix from the template (everything before the $ placeholder).
2. Checks if the user's input already includes the prefix.
3. Prepends the prefix automatically if missing.

This ensures the generated settings-security4.xml always contains well-formed source values like env:MVN_PASSWORD.

Testing

• All 468 tests in maven-cli pass.
• Manually verified that mvn --enc init now writes the correct env: prefix and mvn --enc encrypt succeeds afterward.

---

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