chore: remove go4.org dependency and associated telemetry packages

Removed go4.org and its transitive dependencies from go.mod and go.sum:
- go4.org (unused dependency)
- google.golang.org/api/* packages
- google.golang.org/genproto/* packages
- cloud.google.com/go/* packages
- gocloud.dev/* packages

Total reduction: ~4.9 MB of unnecessary telemetry dependencies.
All functionality preserved through vendored sevenzip package.

go.mod

@@ -5,18 +5,25 @@ go 1.25.0
 require (
 	github.com/ArcadiaLin/go-epub v0.1.1
 	github.com/a-h/templ v0.3.977
-	github.com/bodgit/sevenzip v1.6.1
+	github.com/andybalholm/brotli v1.2.0
+	github.com/bodgit/plumbing v1.3.0
+	github.com/bodgit/windows v1.0.1
 	github.com/fsnotify/fsnotify v1.9.0
 	github.com/go-playground/validator/v10 v10.30.1
 	github.com/golang-jwt/jwt/v5 v5.3.1
 	github.com/google/uuid v1.6.0
 	github.com/gorilla/websocket v1.5.3
+	github.com/hashicorp/golang-lru/v2 v2.0.7
 	github.com/jackc/pgx/v5 v5.8.0
+	github.com/klauspost/compress v1.18.4
 	github.com/labstack/echo-jwt/v4 v4.4.0
 	github.com/labstack/echo/v4 v4.15.1
 	github.com/nwaples/rardecode v1.1.3
+	github.com/pierrec/lz4/v4 v4.1.25
 	github.com/skip2/go-qrcode v0.0.0-20200617195104-da1b6568686e
+	github.com/spf13/afero v1.15.0
 	github.com/stretchr/testify v1.11.1
+	github.com/ulikunitz/xz v0.5.15
 	github.com/yuin/goldmark v1.7.16
 	github.com/yuin/goldmark-highlighting v0.0.0-20220208100518-594be1970594
 	golang.org/x/crypto v0.48.0
@@ -25,35 +32,25 @@ require (
 
 require (
 	github.com/alecthomas/chroma v0.10.0 // indirect
-	github.com/andybalholm/brotli v1.2.0 // indirect
-	github.com/bodgit/plumbing v1.3.0 // indirect
-	github.com/bodgit/windows v1.0.1 // indirect
 	github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc // indirect
 	github.com/dlclark/regexp2 v1.11.5 // indirect
 	github.com/gabriel-vasile/mimetype v1.4.13 // indirect
 	github.com/go-playground/locales v0.14.1 // indirect
 	github.com/go-playground/universal-translator v0.18.1 // indirect
 	github.com/google/go-cmp v0.7.0 // indirect
-	github.com/hashicorp/golang-lru/v2 v2.0.7 // indirect
 	github.com/jackc/pgpassfile v1.0.0 // indirect
 	github.com/jackc/pgservicefile v0.0.0-20240606120523-5a60cdf6a761 // indirect
 	github.com/jackc/puddle/v2 v2.2.2 // indirect
-	github.com/klauspost/compress v1.18.4 // indirect
 	github.com/kr/pretty v0.3.1 // indirect
 	github.com/labstack/gommon v0.4.2 // indirect
 	github.com/leodido/go-urn v1.4.0 // indirect
 	github.com/mattn/go-colorable v0.1.14 // indirect
 	github.com/mattn/go-isatty v0.0.20 // indirect
-	github.com/pierrec/lz4/v4 v4.1.25 // indirect
 	github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2 // indirect
 	github.com/rogpeppe/go-internal v1.14.1 // indirect
-	github.com/spf13/afero v1.15.0 // indirect
-	github.com/stretchr/objx v0.5.3 // indirect
-	github.com/ulikunitz/xz v0.5.15 // indirect
 	github.com/valyala/bytebufferpool v1.0.0 // indirect
 	github.com/valyala/fasttemplate v1.2.2 // indirect
 	github.com/xyproto/randomstring v1.2.0 // indirect
-	go4.org v0.0.0-20260112195520-a5071408f32f // indirect
 	golang.org/x/net v0.50.0 // indirect
 	golang.org/x/sync v0.19.0 // indirect
 	golang.org/x/sys v0.41.0 // indirect