feat: Enhance wails doctor with WebKit fallback support

Improves the doctor command to better detect WebKit dependencies across
different Linux distributions by adding fallback package support.

## Changes Made:

### Enhanced Package Manager Detection:
- **APT (Debian/Ubuntu)**: Added WebKit 4.1 → 4.0 fallback support
- **DNF (Fedora/RHEL)**: Added webkit2gtk4.0-devel fallback for older systems
- **Zypper (SUSE)**: Added webkit2gtk4_1-devel for modern SUSE distributions
- **Emerge (Gentoo)**: Added support for both webkit-gtk:6 and webkit-gtk:4 slots
- **Pacman (Arch)**: Added fallback from webkit2gtk-4.1 to webkit2gtk

### Improved Developer Experience:
- Doctor command now tries newer WebKit versions first, falls back gracefully
- Provides more accurate dependency detection across distributions
- Better guidance for developers on different Linux systems

### How It Works:
- Each package manager lists multiple WebKit package options in order of preference
- The dependency system tries packages in order until it finds one that's available
- Developers get appropriate installation commands for their specific distribution

This complements the nfpm overrides by ensuring developers can properly
set up their development environment regardless of distribution.

🤖 Generated with [Claude Code](https://claude.ai/code)

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

Author: leaanthony

v3/internal/doctor/packagemanager/apt.go

@@ -30,6 +30,7 @@ func (a *Apt) Packages() Packagemap {
 		},
 		"webkit2gtk": []*Package{
 			{Name: "libwebkit2gtk-4.1-dev", SystemPackage: true, Library: true},
+			{Name: "libwebkit2gtk-4.0-dev", SystemPackage: true, Library: true},
 		},
 		"gcc": []*Package{
 			{Name: "build-essential", SystemPackage: true},

v3/internal/doctor/packagemanager/dnf.go

@@ -31,7 +31,7 @@ func (y *Dnf) Packages() Packagemap {
 		"webkit2gtk": []*Package{
 			{Name: "webkit2gtk4.1-devel", SystemPackage: true, Library: true},
 			{Name: "webkit2gtk3-devel", SystemPackage: true, Library: true},
-			// {Name: "webkitgtk3-devel", SystemPackage: true, Library: true},
+			{Name: "webkit2gtk4.0-devel", SystemPackage: true, Library: true},
 		},
 		"gcc": []*Package{
 			{Name: "gcc-c++", SystemPackage: true},

v3/internal/doctor/packagemanager/emerge.go

@@ -31,6 +31,7 @@ func (e *Emerge) Packages() Packagemap {
 		},
 		"webkit2gtk": []*Package{
 			{Name: "net-libs/webkit-gtk:6", SystemPackage: true, Library: true},
+			{Name: "net-libs/webkit-gtk:4", SystemPackage: true, Library: true},
 		},
 		"gcc": []*Package{
 			{Name: "sys-devel/gcc", SystemPackage: true},

v3/internal/doctor/packagemanager/pacman.go

@@ -31,6 +31,7 @@ func (p *Pacman) Packages() Packagemap {
 		},
 		"webkit2gtk": []*Package{
 			{Name: "webkit2gtk-4.1", SystemPackage: true, Library: true},
+			{Name: "webkit2gtk", SystemPackage: true, Library: true},
 		},
 		"gcc": []*Package{
 			{Name: "gcc", SystemPackage: true},

v3/internal/doctor/packagemanager/zypper.go

@@ -31,6 +31,7 @@ func (z *Zypper) Packages() Packagemap {
 			{Name: "gtk3-devel", SystemPackage: true, Library: true},
 		},
 		"webkit2gtk": []*Package{
+			{Name: "webkit2gtk4_1-devel", SystemPackage: true, Library: true},
 			{Name: "webkit2gtk3-soup2-devel", SystemPackage: true, Library: true},
 			{Name: "webkit2gtk3-devel", SystemPackage: true, Library: true},
 		},