Add automatic merge flow from main to feature/net11-scouting

[T-Gro]

Task

Add a merge flow configuration so that changes pushed to main are automatically merged into feature/net11-scouting, while excluding files that the scouting branch manages independently (SDK versions, dependency versions, TFM).

Exact change

Edit .config/service-branch-merge.json and add the following entry at the end of the "merge-flow-configurations" object (after the "release/dev18.0" entry):

"main": {
    "MergeToBranch": "feature/net11-scouting",
    "ExtraSwitches": "-QuietComments",
    "ResetToTargetPaths": [
        "global.json",
        "eng/Version.Details.xml",
        "eng/Version.Details.props",
        "eng/Versions.props",
        "eng/common/**",
        "eng/TargetFrameworks.props"
    ]
}

The full file should look like:

{
    "merge-flow-configurations": {
        "release/dev17.12": {
            "MergeToBranch": "release/dev17.13",
            "ExtraSwitches": "-QuietComments"
        },
        "release/dev17.13": {
            "MergeToBranch": "release/dev17.14",
            "ExtraSwitches": "-QuietComments"
        },
        "release/dev17.14": {
            "MergeToBranch": "release/dev18.0",
            "ExtraSwitches": "-QuietComments"
        },
        "release/dev18.0": {
            "MergeToBranch": "main",
            "ExtraSwitches": "-QuietComments"
        },
        "main": {
            "MergeToBranch": "feature/net11-scouting",
            "ExtraSwitches": "-QuietComments",
            "ResetToTargetPaths": [
                "global.json",
                "eng/Version.Details.xml",
                "eng/Version.Details.props",
                "eng/Versions.props",
                "eng/common/**",
                "eng/TargetFrameworks.props"
            ]
        }
    }
}

Why these specific exclusions

The feature/net11-scouting branch has its own darc subscription for arcade (.NET Eng - Latest) and its own TFM (net11.0). These files must NOT be overwritten by main's .NET 10 values:

File	Reason
global.json	SDK version managed by arcade-latest darc subscription
eng/Version.Details.xml	Dependency SHAs/versions from the net11 arcade channel
eng/Version.Details.props	Version properties from dependency updates
eng/Versions.props	Package versions from dependency flow
eng/common/**	Arcade shared infrastructure (updated by arcade subscription)
eng/TargetFrameworks.props	The single source of truth TFM — set to net11.0

All other eng/ files (targets, templates, build props, scripts) should flow from main — they contain real code changes.

Workflow

The existing .github/workflows/branch-merge.yml already triggers on main pushes, so no workflow YAML changes are needed.

No other files need to change.