feat: first-class WSL session support

[Bitblade]

Summary

Adds WSL as a third session kind alongside Local and SSH. The New Session
dialog gains a WSL radio that auto-detects installed distros via wsl -l -v,
lets the user pick a Linux working folder (with a Browse button rooted at
\\wsl$\<distro>\~), and optionally pins a -u <user>. The session is then
launched via wsl.exe -d <distro> [-u <user>] --cd <linux-path> -- bash -lc '<cmd>',
so anything you can normally run inside the distro — claude, codex, gh copilot, plain bash — Just Works.

Git status, repo-root detection, sibling-worktree listing, and git worktree add all work for WSL sessions: GitService transparently dispatches to
wsl.exe -d <distro> -- git -C <linuxPath> … when the working folder is a
\\wsl$\ UNC, translating arg-side and stdout-side paths so the rest of the
app keeps seeing Windows-shaped paths.

Why

WSL is increasingly where Claude Code and other agent CLIs live for Windows
users (Linux toolchain, native filesystem speed, easier shell environments).
Before this PR the only way to drive WSL through CodeShellManager was to add
wsl.exe as a custom launch command — no distro picker, no working-folder
field, no git status, no Open in Explorer / right-click → New worktree, no
sleep/wake of a distinct-distro session, etc.

Implementation notes

• SessionKind enum on ShellSession: Local | Ssh | Wsl. The legacy
  IsRemote bool stays as a back-compat shim — its setter promotes
  Local → Ssh so old state.json files that only carried \"IsRemote\": true
  migrate cleanly without any custom converter. IsWsl added for symmetry.
• WSL sessions store WorkingFolder as a \\wsl$\<distro>\… UNC so things
  that touch a Windows-shaped path (Explorer, the dormant sidebar item, the
  active-pane subtitle) need no special-casing. The Linux-side path lives on
  WslWorkingFolder and is what gets passed to wsl.exe --cd.
• GitService routing detects the WSL UNC in its single RunGitFullAsync
  funnel — every higher-level method (status, branch, rev-parse, worktree
  list/add) inherits the routing for free. Two translators handle path
  shape:
  • TranslateUncArgsToLinux: \\wsl$\<distro>\foo → /foo in arg strings,
    only when the distro matches (other-distro UNCs pass through unchanged).
  • TranslateLinuxPathsToUnc: absolute Linux paths in stdout → UNC, with a
    conservative regex that only fires at word boundaries so things like
    refs/heads/main aren't mangled.
• InheritSessionKindFrom consolidates the "clone a session derived from a
  parent" logic used by Duplicate, sibling-worktree, and the new-worktree
  dialog — previously three near-identical inline copies that would have
  drifted as soon as a fourth kind landed.

Test plan

• New WSL session: ＋ → WSL → pick distro → Browse opens at
  \\wsl$\<distro>\<home> → pick a subfolder → Start. Confirm prompt
  lands inside WSL (whoami/pwd look correct).
• Git status: open a WSL session pointed at a repo. Sidebar should
  show the branch and dirty state. Run git status inside the session
  and the dirty dot should match.
• Distro picker / user: switch distros in the combo — name suggestion
  updates. Type a -u user — picker re-seeds at that user's home.
• Right-click on a WSL session → New session here: dialog should open
  in WSL mode pre-filled with the parent's distro/user/folder, not Local
  mode with the UNC.
• Right-click → Open WSL console here: spawns a bare bash session
  inside the same distro+folder.
• Right-click → New worktree from this branch: dialog opens (no
  "not a git repo"), worktree is created via wsl.exe -- git worktree add, the new session opens as WSL (not PS at the UNC) and runs the
  parent's command (claude/etc.) successfully.
• Sleep/wake a WSL session: should persist distro/user/folder through
  state.json and relaunch identically.
• Legacy state.json migration: load an old state.json with
  \"IsRemote\": true SSH sessions — should still deserialize as SSH
  (covered by ShellSessionMigrationTests).
• WSL-less host: WSL radio still appears; the distro combo is empty
  with an inline "No WSL distros found…" hint.
• 252 unit tests pass locally.

Screenshots

(I can add screenshots of the WSL panel + browse picker if helpful — happy
to follow up.)

[Copilot]

Pull request overview

Adds first-class WSL session support across the app (new session creation, launching, git integration, and session derivation flows), alongside existing Local and SSH sessions.

Changes:

• Introduces SessionKind (Local | Ssh | Wsl) on ShellSession, retaining IsRemote as a state.json back-compat shim and adding WSL-specific fields (distro/user/linux working folder).
• Extends the New Session dialog UI/logic to support selecting a WSL distro, optional user, and Linux working directory (with UNC-based browsing).
• Routes Git operations for \\wsl$\... working folders through wsl.exe with path translation so existing git-dependent features work for WSL sessions.

Reviewed changes

Copilot reviewed 15 out of 15 changed files in this pull request and generated 9 comments.

Show a summary per file

File	Description
tests/CodeShellManager.Tests/WslDiscoveryServiceTests.cs	Adds unit coverage for parsing wsl -l -v output and UNC conversion helpers.
tests/CodeShellManager.Tests/ShellSessionTests.cs	Adds tests for SessionKind, IsRemote migration behavior, and WSL arg building/display helpers.
tests/CodeShellManager.Tests/ShellSessionMigrationTests.cs	Adds explicit state.json migration tests for legacy IsRemote and new Kind serialization.
tests/CodeShellManager.Tests/RunInstanceTests.cs	Adds tests for WSL run-command arg building and quote escaping.
tests/CodeShellManager.Tests/NewSessionDialogTests.cs	Adds headless tests for WSL UNC parsing helper(s) in the dialog code-behind.
tests/CodeShellManager.Tests/GitServiceWslRoutingTests.cs	Adds tests for WSL UNC detection and argument/stdout path translation in GitService.
src/CodeShellManager/Views/NewSessionDialog.xaml.cs	Implements WSL mode UI behavior: distro discovery, browse-seeding, UNC parsing, and output fields.
src/CodeShellManager/Views/NewSessionDialog.xaml	Adds WSL radio + WSL configuration panel controls.
src/CodeShellManager/ViewModels/SessionViewModel.cs	Updates display/accent/git-refresh logic to use SessionKind and centralized display helpers.
src/CodeShellManager/Services/WslDiscoveryService.cs	Adds discovery of installed WSL distros and home resolution helpers.
src/CodeShellManager/Services/RunInstance.cs	Enables “Run” commands to execute inside WSL sessions via wsl.exe ... bash -lc.
src/CodeShellManager/Services/GitService.cs	Adds WSL routing through wsl.exe when working directory is a WSL UNC path, with translation helpers.
src/CodeShellManager/Models/ShellSession.cs	Adds SessionKind + WSL fields, WSL arg building, and centralized display/accent helpers.
src/CodeShellManager/MainWindow.xaml.cs	Wires dialog output to session creation, launching WSL sessions, and kind inheritance for derived sessions.
README.md	Documents the new WSL session feature at a high level.

Comments suppressed due to low confidence (1)

src/CodeShellManager/MainWindow.xaml.cs:690

• InheritSessionKindFrom covers Duplicate/worktree-derived sessions, but session-history reopen uses RecentlyClosedEntry which currently only persists IsRemote + SSH fields (no Kind/WslDistro/WslUser/WslWorkingFolder). As a result, reopening a closed WSL session will likely come back as Local and try to run the command on the UNC path. Consider extending RecentlyClosedEntry + the reopen path to persist/restore Kind and WSL fields (or reusing this helper there).

    /// <summary>
    /// Propagates a parent session's <see cref="Models.SessionKind"/> and kind-specific
    /// fields (SSH host/user/port, WSL distro/user) onto a freshly-created child
    /// session. For WSL children it also derives <c>WslWorkingFolder</c> from the
    /// child's <c>WorkingFolder</c>, which the worktree code paths set to a
    /// <c>\\wsl$\&lt;distro&gt;\…</c> UNC. Without this step a new session spawned
    /// from a WSL parent (Duplicate, sibling worktree, new worktree) silently falls
    /// back to <see cref="Models.SessionKind.Local"/> and tries to run the parent's
    /// command (e.g. <c>claude</c>) inside a Windows PowerShell at the UNC path.
    /// </summary>
    private static void InheritSessionKindFrom(Models.ShellSession target, Models.ShellSession source)
    {
        target.Kind = source.Kind;
        if (source.Kind == Models.SessionKind.Ssh)
        {
            target.SshUser = source.SshUser;
            target.SshHost = source.SshHost;
            target.SshPort = source.SshPort;
            target.SshRemoteFolder = source.SshRemoteFolder;
            return;
        }
        if (source.Kind == Models.SessionKind.Wsl)
        {
            target.WslDistro = source.WslDistro;
            target.WslUser = source.WslUser;

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[Copilot]

Pull request overview

Copilot reviewed 16 out of 16 changed files in this pull request and generated 1 comment.

Comments suppressed due to low confidence (2)

src/CodeShellManager/Services/WslDiscoveryService.cs:109

• Parse() splits each row on spaces, which breaks if a WSL distro name contains spaces (e.g. an imported distro named "My Distro"). In that case name/state/version tokens shift and the picker + downstream -d <distro> invocations will be wrong. Consider parsing by fixed columns (based on header offsets) or by taking the last 2 columns as STATE/VERSION and treating the remainder as the name (after optional leading *).

            // Header row: "  NAME                   STATE           VERSION".
            // Detect by the presence of the literal "NAME" token and skip.
            if (line.TrimStart().StartsWith("NAME", StringComparison.Ordinal)) continue;

            var tokens = line.Split(new[] { ' ' }, StringSplitOptions.RemoveEmptyEntries);
            if (tokens.Length < 2) continue;

            bool isDefault = tokens[0] == "*";
            int idx = isDefault ? 1 : 0;
            if (tokens.Length - idx < 1) continue;

            string name = tokens[idx];
            string state = tokens.Length - idx >= 2 ? tokens[idx + 1] : "";
            int version = 0;
            if (tokens.Length - idx >= 3) int.TryParse(tokens[idx + 2], out version);

            results.Add(new WslDistro(name, version, isDefault, state));

src/CodeShellManager/Services/WslDiscoveryService.cs:140

• GetDistroHomeAsync builds wsl.exe args via string interpolation (-d {distro} -u {user}) without quoting. This will fail for distro/user values containing spaces and also makes argument boundaries ambiguous. Use the same quoting helper as the other wsl.exe call sites (e.g. ShellSession.QuoteForCmd) or switch to ProcessStartInfo.ArgumentList to avoid manual quoting entirely.

        try
        {
            string args = $"-d {distro}";
            if (!string.IsNullOrEmpty(normalizedUser)) args += $" -u {normalizedUser}";
            args += " -- sh -c \"cd ~ && pwd\"";

[Copilot]

Pull request overview

Copilot reviewed 16 out of 16 changed files in this pull request and generated 2 comments.