Rebrand MMTL to MeBox (name, logo, Docker image) (#17)

* Rebrand MMTL to MeBox across codebase and assets

Rename the project display name, Go module path, environment variable
prefix (MEBOX_*), Docker image references, and UI branding from MMTL/mmtl
to MeBox/mebox. Replace logo assets with the new MeBox icon and keep
legacy SQLite migration support for existing mmtl.db deployments.

Co-authored-by: truewhile <truewhile@users.noreply.github.com>

* Fix logo icons: use cube-only crop without truncated text

Previous icon generation cropped too much of the source image, including
partial MeBox wordmark text that was cut off in square icon containers.
Regenerate logo-64/192/512, favicon, and SVG from cube-only region.

Co-authored-by: truewhile <truewhile@users.noreply.github.com>

---------

Co-authored-by: Cursor Agent <cursoragent@cursor.com>
Co-authored-by: truewhile <truewhile@users.noreply.github.com>

internal/service/media_series_key.go

@@ -6,7 +6,7 @@ import (
 	"regexp"
 	"strings"
 
-	"github.com/ShukeBta/MMTL/internal/model"
+	"github.com/truewhile/MeBox/internal/model"
 )
 
 var episodicPathRE = regexp.MustCompile(`(?i)[\\/](?:电视剧|剧集|连续剧|短剧|国产剧|国剧|大陆剧|华语剧|国产电视剧|大陆电视剧|华语电视剧|欧美剧|欧美电视剧|美剧|英剧|日韩剧|日韩电视剧|日剧|韩剧|港剧|台剧|港台剧|泰剧|综艺|纪录片|儿童|动漫|番剧|国漫|日番|韩漫|美漫|欧美动漫|欧美动画|其他动漫|tv|series|shows?|season[\s._-]*\d|s\d{1,2}(?:[\s._-]|[\\/])|special[\s._-]*episodes?|specials?|sp|ovas?|oads?|extras?|bonus(?:es)?|omake|特别篇|特別篇|番外篇?|特典|外传|外傳|总集篇|總集篇)[\\/]`)