ci(devops): Windows runner bash 改由 Machine PATH 提供，workflow 回退干净 shell: bash

runner 主机已把 C:\Program Files\Git\bin 加入 Machine PATH（forgejo-runner
以 LocalSystem 运行，已重启生效，where bash 可解析），故撤掉 cf468f5 的
绝对路径 hack，provision/compile 两步回到 shell: bash + sh scripts/ci/...。

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Y2Wdwo7SmgBJU37cBrkhPK

.gitea/workflows/build-windows.yml

@@ -28,11 +28,11 @@ jobs:
       - uses: actions/checkout@v4
 
       - name: Provision (idempotent — auto-runs if host not initialized)
-        shell: 'C:\Program Files\Git\bin\bash.exe --noprofile --norc -eo pipefail {0}'
+        shell: bash
         run: sh scripts/ci/provision-windows.sh
 
       - name: Compile (Flutter Windows)
-        shell: 'C:\Program Files\Git\bin\bash.exe --noprofile --norc -eo pipefail {0}'
+        shell: bash
         run: sh scripts/ci/compile-windows.sh "${{ inputs.ver || 'v1.0.4' }}"
 
       - name: Upload windows artifact

.gitea/workflows/deploy-client.yml

@@ -122,11 +122,11 @@ jobs:
       - uses: actions/checkout@v4
 
       - name: Provision (idempotent — auto-runs if host not initialized)
-        shell: 'C:\Program Files\Git\bin\bash.exe --noprofile --norc -eo pipefail {0}'
+        shell: bash
         run: sh scripts/ci/provision-windows.sh
 
       - name: Compile (Flutter Windows)
-        shell: 'C:\Program Files\Git\bin\bash.exe --noprofile --norc -eo pipefail {0}'
+        shell: bash
         run: sh scripts/ci/compile-windows.sh "${{ gitea.ref_name }}"
 
       - name: Upload windows artifacts