[Windows] LSP servers fail to spawn: CreateProcess rejects \\?\ extended-path cwd ("The system cannot find the path specified")

[Qiiks]

Short description

On Windows, every LSP server spawn fails because the daemon passes a \\?\-prefixed (extended-length) project root as the child process working directory. CreateProcess does not support extended-length paths in lpCurrentDirectory (documented Win32 limitation), so the spawn dies with ERROR_PATH_NOT_FOUND → "The system cannot find the path specified." → AFT reports all LSP servers as not installed/unusable.

Observed behavior

aft-opencode v0.49.0, Windows 10 0.26100, project root C:\Users\Sanveed:

[aft-lsp] [ses_...] failed to spawn TypeScript Language Server: server not ready: server crashed during initialize: server not ready: language server TypeScript disconnected while waiting for 'initialize'; stderr (last 64 lines):
  The system cannot find the path specified.
[aft] ... exited TypeScript \\?\C:\Users\Sanveed

• The server package is installed and healthy: typescript-language-server --version → 5.3.0, and a full LSP initialize handshake succeeds when spawned with a normal cwd.
• aft_inspect reports "servers: not installed" because the daemon can't spawn them.
• The same \\?\ root also breaks unrelated child spawns in that session, e.g. artifact cache key: git root-commit probe failed after retries (spawn failed: program not found).

Root cause (source-verified, current main)

1. crates/aft/src/lsp/roots.rs:13 — find_workspace_root calls std::fs::canonicalize(file_path). On Windows, Rust's canonicalize returns \\?\-prefixed extended-length paths (e.g. \\?\C:\Users\Sanveed).
2. crates/aft/src/lsp/manager.rs — that root flows into LspClient::spawn → crates/aft/src/lsp/client.rs:165 — .current_dir(&root).
3. CreateProcess with lpCurrentDirectory = \\?\... → ERROR_PATH_NOT_FOUND.

Independent repro (same error class through .NET's Process.Start, which uses CreateProcess):

cwd=C:\Users\Sanveed          => STARTED ok
cwd=\\?\C:\Users\Sanveed      => FAILED: "The directory name is invalid"

Note the codebase already strips \\?\ for URI conversion (position.rs:160-170), and the opencode plugin's normalizeWindowsRoot() does the same for project-root canonicalization — but the LSP spawn cwd path is not normalized.

Expected behavior

LSP servers spawn successfully on Windows. Either:

• strip the \\?\ prefix from the root before .current_dir(), or
• avoid canonicalize for the workspace root on Windows (walk-up marker search works fine on non-canonical paths).

Environment

• AFT plugin: 0.49.0 / aft binary 0.49.0
• OS: Windows 10 22H2 (26100), x64
• Host: OpenCode, aft-opencode plugin
• Affects every session regardless of project (any absolute path canonicalizes to \\?\ on Windows)