refactor(v3): fold webview2 module into v3/internal/webview2 (#5711)

The webview2 binding was a separate Go module (github.com/wailsapp/wails/webview2)
whose only consumer is v3. Keeping it separate forced a release dance: tag
webview2, then bump v3's go.mod (automated via a nightly sync workflow) before any
binding change could ship in a v3 release.

Fold it into the v3 module under internal/ (compiler-enforced no external import),
which removes the dance entirely: edit-and-go, single module.

- git mv webview2 -> v3/internal/webview2; drop its go.mod/go.sum
- rewrite import paths in the binding + 11 v3 consumers
- drop ./webview2 from go.work; go mod tidy (go-winloader now direct)
- add missing //go:build windows to 8 edge files that lacked it (latent: the
  binding was never part of v3's cross-platform 'go build ./...' before)
- CI: delete release-webview2.yml, remove the webview2-sync step from the v3
  nightly, drop webview2/** triggers and webview2/go.sum cache keys

For v4 the plan is to copy the directory in rather than share a module.

Co-authored-by: taliesin-ai <lea.anthony@gmail.com>

Author: taliesin-ai

go.work

@@ -2,5 +2,4 @@ go 1.25.0
 
 use (
 	./v3
-	./webview2
 )

v3/UNRELEASED_CHANGELOG.md

@@ -30,7 +30,6 @@ require (
 	github.com/stretchr/testify v1.11.1
 	github.com/tc-hib/winres v0.3.1
 	github.com/wailsapp/task/v3 v3.40.1-patched3
-	github.com/wailsapp/wails/webview2 v1.0.28
 	github.com/zalando/go-keyring v0.2.6
 	golang.org/x/sys v0.43.0
 	golang.org/x/term v0.42.0
@@ -109,7 +108,7 @@ require (
 	github.com/huandu/xstrings v1.5.0 // indirect
 	github.com/jaypipes/pcidb v1.1.1 // indirect
 	github.com/jbenet/go-context v0.0.0-20150711004518-d14ea06fba99 // indirect
-	github.com/jchv/go-winloader v0.0.0-20250406163304-c1995be93bd1 // indirect
+	github.com/jchv/go-winloader v0.0.0-20250406163304-c1995be93bd1
 	github.com/joho/godotenv v1.5.1 // indirect
 	github.com/kevinburke/ssh_config v1.4.0 // indirect
 	github.com/klauspost/compress v1.18.3 // indirect

v3/go.mod

@@ -356,8 +356,6 @@ github.com/ulikunitz/xz v0.5.15 h1:9DNdB5s+SgV3bQ2ApL10xRc35ck0DuIX/isZvIk+ubY=
 github.com/ulikunitz/xz v0.5.15/go.mod h1:nbz6k7qbPmH4IRqmfOplQw/tblSgqTqBwxkY0oWt/14=
 github.com/wailsapp/task/v3 v3.40.1-patched3 h1:i6O1WNdSur9CGaiMDIYGjsmj/qS4465zqv+WEs6sPRs=
 github.com/wailsapp/task/v3 v3.40.1-patched3/go.mod h1:jIP48r8ftoSQNlxFP4+aEnkvGQqQXqCnRi/B7ROaecE=
-github.com/wailsapp/wails/webview2 v1.0.28 h1:rWBjaGGfzqVOH7TPy1s9VoP8jWNz0gmBd8ZkUKHi0qQ=
-github.com/wailsapp/wails/webview2 v1.0.28/go.mod h1:zdM4jcO1IaC61RiJL5F1BzgoqBHFIdacz8gPr5exr0o=
 github.com/xanzy/ssh-agent v0.3.3 h1:+/15pJfg/RsTxqYcX6fHqOXZwwMP+2VyYWJeWM2qQFM=
 github.com/xanzy/ssh-agent v0.3.3/go.mod h1:6dzNDKs0J9rVPHPhaGCukekBHKqfl+L3KghI1Bc68Uw=
 github.com/xi2/xz v0.0.0-20171230120015-48954b6210f8 h1:nIPpBwaJSVYIxUFsDv3M8ofmx9yWTog9BfvIu0q41lo=

v3/go.sum

@@ -8,7 +8,7 @@ import (
 	"io"
 	"net/http"
 
-	"github.com/wailsapp/wails/webview2/pkg/edge"
+	"github.com/wailsapp/wails/v3/internal/webview2/pkg/edge"
 )
 
 // NewRequest creates as new WebViewRequest for chromium. This Method must be called from the Main-Thread!

v3/internal/assetserver/webview/request_windows.go

@@ -2,7 +2,7 @@
 
 package capabilities
 
-import "github.com/wailsapp/wails/webview2/webviewloader"
+import "github.com/wailsapp/wails/v3/internal/webview2/webviewloader"
 
 type version string
 

v3/internal/capabilities/capabilities_windows.go

@@ -7,7 +7,7 @@ import (
 	"strings"
 
 	"github.com/wailsapp/wails/v3/internal/lo"
-	"github.com/wailsapp/wails/webview2/webviewloader"
+	"github.com/wailsapp/wails/v3/internal/webview2/webviewloader"
 )
 
 func getInfo() (map[string]string, bool) {