feat(upgrade-all): skip pip/pipx when uv is managing Python packages

Added detection to avoid redundant pip/pipx upgrades when UV is present,
since UV is designed to replace both tools.

Rationale:
- UV is a modern, faster replacement for pip and pipx
- Running pip/pipx upgrades alongside UV is redundant
- UV handles both package installation (pip) and tool management (pipx)
- Reduces upgrade time and eliminates conflicting package managers

Changes:
Stage 2 (Package Managers):
- pip: Skip with "pip (uv is managing Python packages)"
- pipx: Skip with "pipx (uv is managing Python tools)"

Stage 4 (User Packages):
- pipx packages: Skip with "pipx packages (uv tools handle this)"

Detection logic:
if command -v uv >/dev/null 2>&1; then
  log_skip "pip (uv is managing Python packages)"
fi

When UV is NOT present:
- pip/pipx upgrade normally as before
- No behavior change for systems without UV

When UV IS present:
Stage 2:
  ⏭ pip (uv is managing Python packages)
  ✓ uv (0.5.11 at /home/user/.local/bin/uv)
  ⏭ pipx (uv is managing Python tools)

Stage 4:
  ✓ uv tool: ansible
  ✓ uv tool: black
  ...
  ⏭ pipx packages (uv tools handle this)

Benefits:
- Prevents package manager conflicts
- Reduces upgrade time when UV is present
- Clear messaging about which tool is managing Python packages
- Encourages modern tooling adoption

🤖 Generated with Claude Code

Co-Authored-By: Claude <noreply@anthropic.com>

Author: AI Assistant

scripts/upgrade_all.sh

@@ -198,8 +198,11 @@ stage_2_managers() {
 
 	# Language-specific package managers
 	if command -v pip3 >/dev/null 2>&1; then
+		# Skip pip if uv is managing Python packages
+		if command -v uv >/dev/null 2>&1; then
+			log_skip "pip (uv is managing Python packages)"
 		# Check if pip module is actually available
-		if ! python3 -m pip --version >/dev/null 2>&1; then
+		elif ! python3 -m pip --version >/dev/null 2>&1; then
 			log_skip "pip (python3 has no pip module)"
 		elif [ "$DRY_RUN" = "1" ]; then
 			log_info "DRY-RUN: pip upgrade"
@@ -237,7 +240,10 @@ stage_2_managers() {
 	fi
 
 	if command -v pipx >/dev/null 2>&1; then
-		if [ "$DRY_RUN" = "1" ]; then
+		# Skip pipx if uv is managing Python tools
+		if command -v uv >/dev/null 2>&1; then
+			log_skip "pipx (uv is managing Python tools)"
+		elif [ "$DRY_RUN" = "1" ]; then
 			log_info "DRY-RUN: pip3 install --upgrade pipx"
 		else
 			# Check if in virtualenv - skip --user flag if so
@@ -556,7 +562,10 @@ stage_4_user_packages() {
 
 	# Pipx packages
 	if command -v pipx >/dev/null 2>&1; then
-		if [ "$DRY_RUN" = "1" ]; then
+		# Skip pipx packages if uv is managing Python tools
+		if command -v uv >/dev/null 2>&1; then
+			log_skip "pipx packages (uv tools handle this)"
+		elif [ "$DRY_RUN" = "1" ]; then
 			log_info "DRY-RUN: pipx upgrade-all"
 		else
 			local temp_log=$(mktemp)