fix(DEN-1616,DEN-1634): harden Windows zed develop -c

[ORESoftware]

Linear

• DEN-1616 — suppress implicit PowerShell profiles
• DEN-1634 — normalize Windows child-process current directories
• Parent external certification: DEN-1614

Problem

Two Windows process-boundary defects were exposed by native clean-room testing:

1. PowerShell command mode used -NoLogo -Command and could therefore execute user profile code implicitly.
2. Project discovery correctly retained canonical Windows paths such as \\?\C:\..., but those identity paths are not accepted consistently as a child-process current directory. A child shell could inherit the nested caller directory while ZED_DEV_PROJECT_ROOT identified the owning project.

Semantic correction

• PowerShell command mode now uses -NoLogo -NoProfile -NonInteractive -Command <script> for pwsh, pwsh.exe, powershell, and powershell.exe.
• Explicit interactive PowerShell startup remains untouched.
• cmd.exe remains /D /S /C <script> so AutoRun stays disabled.
• ZED_DEV_PROJECT_ROOT, cache paths, and evidence retain canonical filesystem identity.
• Only the Windows child-process cwd is converted from:
  • \\?\C:\path to C:\path;
  • \\?\UNC\server\share\path to \\server\share\path.
• The conversion works on UTF-16 code units, preserving Unicode paths without lossy string conversion.
• Ordinary drive, UNC, and device paths remain unchanged.

This preserves both sides of the design: canonical path identity for Zed state and a process-compatible equivalent path for native child launch.

Tests and documentation

• typed PowerShell, cmd.exe, generic-shell, and interactive argument-vector tests;
• both shared cross-platform shell matrices synchronized to one PowerShell contract;
• Unicode disk, verbatim UNC, ordinary drive/UNC, and device-path normalization tests;
• native Windows profile canary using real PowerShell profile locations;
• native child-cwd assertion proving the shell starts at the project owning the fixture manifest;
• read-only Windows Server 2022 workflow with formatting, focused unit/integration tests, real binary execution, source-cleanliness proof, and Clippy with warnings denied;
• durable trust-boundary documentation in docs/powershell-command-mode.md.

Validation evidence

The complete repository matrix passed on reviewed head 815edd140e5cceb21983c60ff7e03bb99466567b except for one Windows Clippy needless_return diagnostic:

• CI 30887528618 — passed;
• develop-shell 30887528562 — passed;
• Nix 30887528774 — passed;
• mise 30887528625 — passed;
• polyglot 30887528626 — passed;
• OCI 30887528656 — passed;
• repository hardening 30887528682 — passed;
• formal review 30887528596 — passed;
• agents policy 30887528970 — passed.

The only source delta after that matrix is the equivalent tail-expression form in the Windows cwd helper. The exact correction was validated against:

• all three Windows cwd normalization tests;
• PowerShell command arguments;
• both shared shell matrices;
• rustfmt; and
• Clippy with -D warnings.

The validation job completed every check successfully; its final push was rejected only because a concurrent evidence commit had already advanced the branch. The checked-in source at final head 3523e577493ce3403ca75f19653f55f6de6ab81c contains that validated tail expression. Normal protected workflows were then triggered from a connector-authored evidence commit.

No credential, registry, cloud service, or production account is used.

[linear-code]

DEN-1616

DEN-1614

DEN-1634