chore: import upstream snapshot with attribution

tools/skillgen/fragments/shell/posix.md

@@ -0,0 +1,39 @@
+```bash
+# Detect the correct Python interpreter (handles uv tool, pipx, venv, system installs)
+PYTHON=""
+GRAPHIFY_BIN=$(which graphify 2>/dev/null)
+# 1. uv tool installs — most reliable on modern Mac/Linux
+if [ -z "$PYTHON" ] && command -v uv >/dev/null 2>&1; then
+    _UV_PY=$(uv tool run --from graphifyy python -c "import sys; print(sys.executable)" 2>/dev/null)
+    if [ -n "$_UV_PY" ]; then PYTHON="$_UV_PY"; fi
+fi
+# 2. Read shebang from graphify binary (pipx and direct pip installs)
+if [ -z "$PYTHON" ] && [ -n "$GRAPHIFY_BIN" ]; then
+    _SHEBANG=$(head -1 "$GRAPHIFY_BIN" | tr -d '#!')
+    case "$_SHEBANG" in
+        *[!a-zA-Z0-9/_.@-]*) ;;
+        *) "$_SHEBANG" -c "import graphify" 2>/dev/null && PYTHON="$_SHEBANG" ;;
+    esac
+fi
+# 3. Fall back to python3
+if [ -z "$PYTHON" ]; then PYTHON="python3"; fi
+if ! "$PYTHON" -c "import graphify" 2>/dev/null; then
+    if command -v uv >/dev/null 2>&1; then
+        uv tool install --upgrade graphifyy -q 2>&1 | tail -3
+        _UV_PY=$(uv tool run --from graphifyy python -c "import sys; print(sys.executable)" 2>/dev/null)
+        if [ -n "$_UV_PY" ]; then PYTHON="$_UV_PY"; fi
+    else
+        "$PYTHON" -m pip install graphifyy -q 2>/dev/null \
+          || "$PYTHON" -m pip install graphifyy -q --break-system-packages 2>&1 | tail -3
+    fi
+fi
+# Write interpreter path for all subsequent steps (persists across invocations)
+mkdir -p graphify-out
+"$PYTHON" -c "import sys; open('graphify-out/.graphify_python', 'w', encoding='utf-8').write(sys.executable)"
+# Save scan root so `graphify update` (no args) knows where to look next time
+echo "$(cd INPUT_PATH && pwd)" > graphify-out/.graphify_root
+```
+
+If the import succeeds, print nothing and move straight to Step 2.
+
+**In every subsequent bash block, replace `python3` with `$(cat graphify-out/.graphify_python)` to use the correct interpreter.**

tools/skillgen/fragments/shell/powershell.md

@@ -0,0 +1,61 @@
+```powershell
+# Detect Python with graphify — uv/pipx-aware (fixes #831)
+New-Item -ItemType Directory -Force -Path graphify-out | Out-Null
+$GRAPHIFY_PYTHON = $null
+
+function Find-GraphifyPython {
+    # 1. uv tool install — 'uv tool dir' is authoritative, respects UV_TOOL_DIR automatically
+    if (Get-Command uv -ErrorAction SilentlyContinue) {
+        $uvDir = (uv tool dir 2>$null).Trim()
+        if ($uvDir) {
+            $py = Join-Path $uvDir "graphifyy\Scripts\python.exe"
+            if (Test-Path $py) {
+                & $py -c "import graphify" 2>$null
+                if ($LASTEXITCODE -eq 0) { return $py }
+            }
+        }
+    }
+    # 2. pipx install — 'pipx environment' respects PIPX_HOME automatically
+    if (Get-Command pipx -ErrorAction SilentlyContinue) {
+        $venvs = (pipx environment --value PIPX_LOCAL_VENVS 2>$null).Trim()
+        if ($venvs) {
+            $py = Join-Path $venvs "graphifyy\Scripts\python.exe"
+            if (Test-Path $py) {
+                & $py -c "import graphify" 2>$null
+                if ($LASTEXITCODE -eq 0) { return $py }
+            }
+        }
+    }
+    # 3. Active venv / conda / pip-into-current-env
+    $pyCmd = Get-Command python -ErrorAction SilentlyContinue
+    if ($pyCmd) {
+        & $pyCmd.Source -c "import graphify" 2>$null
+        if ($LASTEXITCODE -eq 0) {
+            return (& $pyCmd.Source -c "import sys; print(sys.executable)").Trim()
+        }
+    }
+    return $null
+}
+
+# Try to find the right Python (uv → pipx → active env)
+$GRAPHIFY_PYTHON = Find-GraphifyPython
+
+# Not found — install then re-detect
+if (-not $GRAPHIFY_PYTHON) {
+    if (Get-Command uv -ErrorAction SilentlyContinue) {
+        uv tool install --upgrade graphifyy -q 2>&1 | Select-Object -Last 3
+    } else {
+        pip install graphifyy -q 2>&1 | Select-Object -Last 3
+    }
+    $GRAPHIFY_PYTHON = Find-GraphifyPython
+}
+
+# Save interpreter path — all subsequent steps read this
+$GRAPHIFY_PYTHON | Out-File -FilePath graphify-out\.graphify_python -Encoding utf8 -NoNewline
+# Save scan root so `graphify update` (no args) knows where to look next time
+(Resolve-Path INPUT_PATH).Path | Out-File -FilePath graphify-out\.graphify_root -Encoding utf8 -NoNewline
+```
+
+If the import succeeds, print nothing and move straight to Step 2.
+
+**In every subsequent block, run Python through the saved interpreter — `& (Get-Content graphify-out\.graphify_python)` in place of a bare `python3` — so every step uses the interpreter that actually has graphify.**