#1135: Add PowerShell environment initialization

[cap-juan]

This PR fixes #1135

Implemented changes:

• Added PowerShell shell integration for IDEasy.
• Added automatic IDEasy environment initialization when PowerShell starts inside an IDEasy project.
• Added PowerShell equivalents for the existing ide, icd, and claude shell functions.
• Added PowerShell command completion support where supported by the installed PowerShell version.
• Added automatic configuration and cleanup of the current user's PowerShell profile during installation and uninstallation.
• Added functions.ps1 to the IDEasy installation artifacts.
• Kept the PowerShell behavior aligned with the existing Bash integration.

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Testing instructions

1. Check out the PR branch and build/install IDEasy using the normal local development workflow.

2. Verify that the PowerShell integration script was installed:
   Test-Path "$env:IDE_ROOT\_ide\installation\functions.ps1"

3. The command should return True.

4. Close all existing PowerShell sessions.

5. Open a new PowerShell window directly inside an IDEasy project.

6. Verify that ide is loaded as a PowerShell function:
   Get-Command ide

7. The command type should be Function.

8. Verify that the IDEasy environment was initialized automatically:

$env:IDE_HOME
$env:MAVEN_ARGS

9. Both variables should contain the values for the current IDEasy project.

10. Verify that Maven can be executed without running ide first:
    mvn --version

11. Verify manual environment refresh after changing directories:

Set-Location "$env:IDE_ROOT"
Set-Location "$env:IDE_ROOT\IDEasy"
ide
$env:MAVEN_ARGS

12. MAVEN_ARGS should be set after running ide.

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Checklist for this PR

Make sure everything is checked before merging this PR. For further info please also see
our DoD.

• When running mvn clean test locally all tests pass and build is successful
• PR title is of the form #«issue-id»: «brief summary» (e.g. #921: fixed setup.bat). If no issue ID exists, title only.
• PR top-level comment summarizes what has been done and contains link to addressed issue(s)
• PR and issue(s) have suitable labels
• Issue is set to In Progress and assigned to you or there is no issue (might happen for very small PRs)
• You followed all coding conventions
• You have added the issue implemented by your PR in CHANGELOG.adoc unless issue is labeled
  with internal
• You have formulated clear instructions on how to test your contribution under "Testing instructions"

Checklist for tool commandlets

Have you added a new «tool» as commandlet? There are the following additional checks:

• The tool can be installed automatically (during setup via settings) or via the commandlet call
• The tool is isolated in its IDEasy project, see Sandbox Principle
• The new tool is added to the table of tools in LICENSE.asciidoc
• The new commandlet is a command-wrapper for «tool»
• Proper help texts for all supported languages are added here
• The new commandlet installs potential dependencies automatically
• The variables «TOOL»_VERSION and «TOOL»_EDITION are honored by your commandlet
• The new commandlet is tested on all platforms it is available for or tested on all platforms that are in scope of the linked issue

[CLAassistant]

All committers have signed the CLA.

[coveralls]

Coverage Report for CI Build 30450098251

Coverage increased (+0.04%) to 72.632%

Details

• Coverage increased (+0.04%) from the base build.
• Patch coverage: No coverable lines changed in this PR.
• 77 coverage regressions across 2 files.

Uncovered Changes

No uncovered changes found.

Coverage Regressions

77 previously-covered lines in 2 files lost coverage.

File	Lines Losing Coverage	Coverage
com/devonfw/tools/ide/tool/IdeasyCommandlet.java	76	76.27%
com/devonfw/tools/ide/tool/ide/IdeToolCommandlet.java	1	78.33%

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Coverage Stats

Relevant Lines:	17062
Covered Lines:	12922
Line Coverage:	75.74%
Relevant Branches:	7635
Covered Branches:	5016
Branch Coverage:	65.7%
Branches in Coverage %:	Yes
Coverage Strength:	3.21 hits per line

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💛 - Coveralls

[samuelkos17]

Good job! IMHO this is a nice implementation which adds the functionality requested in #1135. I've ran through your test instructions and everything worked perfectly fine. I have a small suggestion though concerning your method structure. Also you could think about adding tests for the changes you made.