fix: resolve Gitea Actions authentication issue in nix-update workflow

- Replace actions/checkout@v4 with manual git clone using token-embedded
  URL to fix 'could not read Username: terminal prompts disabled' error
- Disable GIT_TERMINAL_PROMPT and GIT_ASKPASS to prevent interactive prompts
- Consolidate git config setup into checkout step

Package updates:
- beads: 0.47.1 -> 0.47.2
- opencode: 1.1.18 -> 1.1.25

Beads state sync:
- Close nixpkgs-8jw (Gitea Actions node PATH issue resolved)
- Close nixpkgs-r3u (Gitea Actions nix-update workflow complete)
- Create nixpkgs-8ng (opencode subpackage update requires special args)
- Remove deleted tombstone issues

.gitea/workflows/nix-update.yml

@@ -21,10 +21,26 @@ jobs:
     runs-on: nixos
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v4
-        with:
-          fetch-depth: 0
-          token: ${{ secrets.NIX_UPDATE_TOKEN }}
+        run: |
+          # Disable terminal prompts for all git operations
+          export GIT_TERMINAL_PROMPT=0
+          export GIT_ASKPASS="/bin/echo"
+          
+          # Clone repository with token authentication
+          git clone --depth 0 --no-single-branch \
+            "https://${{ secrets.NIX_UPDATE_TOKEN }}@code.m3ta.dev/m3tam3re/nixpkgs.git" \
+            /workspace/m3tam3re/nixpkgs
+          
+          cd /workspace/m3tam3re/nixpkgs
+          
+          # Configure git author/committer
+          git config --global user.name "${{ env.GIT_AUTHOR_NAME }}"
+          git config --global user.email "${{ env.GIT_AUTHOR_EMAIL }}"
+          git config --global init.defaultBranch master
+          
+          # Verify checkout
+          git status
+          git log --oneline -5
 
       - name: Check for available packages to update
         id: check-packages
@@ -41,11 +57,6 @@ jobs:
             echo "has_flake=false" >> $GITHUB_OUTPUT
           fi
 
-      - name: Setup git config
-        run: |
-          git config --global user.name "${{ env.GIT_AUTHOR_NAME }}"
-          git config --global user.email "${{ env.GIT_AUTHOR_EMAIL }}"
-          git config --global init.defaultBranch master
 
       - name: Update packages
         id: update