[Bug]: PowerShell common.ps1 uses wrong base path for specs directory

从 .specify/scripts/powershell/common.ps1 开始，重点关注 Get-CurrentBranch 和 Get-FeatureDir。在功能分支上运行 .specify/scripts/powershell/setup-plan.ps1 -Json，并检查生成的路径。完成的标准是文件放置在 .specify/specs/ 下，不包含额外的 feature/ 目录，同时现有工作流继续正常运行。

Bug Description

The PowerShell common functions in .specify/scripts/powershell/common.ps1 use incorrect paths, causing spec files to be created in specs/ at the repository root instead of .specify/specs/ as documented and expected by the framework.

Steps to Reproduce

1. Clone a spec-kit project
2. Check out a feature branch (e.g., feature/US123-my-feature)
3. Run .specify/scripts/powershell/setup-plan.ps1 -Json
4. Observe files are created in specs/feature/US123-my-feature/ instead of .specify/specs/US123-my-feature/

Expected Behavior

All spec files should be created under the .specify/specs/ directory as documented throughout the framework and in .specify/specs/README.md.

Actual Behavior

• Files are created in specs/ at the repository root (wrong location)
• When using feature branches like feature/something, an extra nested feature/ directory is created: specs/feature/something/
• This violates the documented .specify/ prefix convention
• Requires manual cleanup after every planning operation

Specify CLI Version

0.2.1

AI Agent

GitHub Copilot

Operating System

Windows 10.0.26200 AMD64

Python Version

3.12.4

Error Logs

Additional Context

Component

Scripts (.specify/scripts/)

AI Agent (if applicable)

Affects all agents that use /speckit.plan, /speckit.tasks, and related commands

Additional Context

• This affects all PowerShell-based workflows

• The bash version (common.sh) likely has similar issues if it exists

• Working fix tested in production: https://ghe.coxautoinc.com/deCipher/TestingbyRallyCards/commit/abc54be

• Root Cause

File: .specify/scripts/powershell/common.ps1

Line 38 (in Get-CurrentBranch function):

$specsDir = Join-Path $repoRoot "specs"

Should be:

$specsDir = Join-Path $repoRoot ".specify/specs"

Line 98 (in Get-FeatureDir function):

Join-Path $repoRoot "specs/$Branch"

Should be:

$dirName = $Branch -replace '^feature/', ''  # Strip branch prefix
Join-Path $repoRoot ".specify/specs/$dirName"

Proposed Fix

function Get-FeatureDir {
    param([string]$RepoRoot, [string]$Branch)
    # Strip feature/ prefix if present for specs directory naming
    $dirName = $Branch -replace '^feature/', ''
    Join-Path $RepoRoot ".specify/specs/$dirName"
}

Also update line 38 in Get-CurrentBranch:

$specsDir = Join-Path $repoRoot ".specify/specs"