feat(05-02): 3-tab layout + files templates + router + main.go S3 wiring
- tablos.templ: TabloDetailPage gains files+activeTab params, 3-tab nav with hx-push-url
- tablos.templ: TabloOverviewTabFragment + TasksTabFragment (wraps KanbanBoard) added
- files.templ: FilesTabFragment, FileUploadForm (hx-encoding=multipart/form-data),
FileListRow, FileListEmpty, FileRowGone, UploadErrorFragment
- files_helpers.go: formatBytes() converts int64 bytes to human-readable string
- router.go: fileDeps FilesDeps param added; TabloTasksTabHandler + file routes wired
- handlers_tablos.go: both TabloDetailPage call sites updated (nil, 'overview')
- main.go: S3_ENDPOINT/S3_BUCKET/S3_REGION env vars read; files.NewStore constructed;
fileDeps wired; nil filesStore allowed when S3 env unset (503 from handlers)
- All test routers updated to pass FilesDeps{} in new param position
a12c5abea6