Add video picker and Discord video attachments.

The picker accepts one MP4 or WebM, the thread lightbox zooms photos, and Discord gets the video as a file on a follow-up message so photo embeds still render.

internal/web/posts.go

@@ -12,6 +12,7 @@ import (
 	"github.com/go-chi/chi/v5"
 	"github.com/google/uuid"
 
+	"plumber/internal/events"
 	"plumber/internal/store"
 )
 
@@ -22,7 +23,14 @@ func (s *Server) handleCreatePost(w http.ResponseWriter, r *http.Request) {
 	if !ok {
 		return
 	}
-	defer cleanup()
+	var media []events.Media
+	held := false
+	defer func() {
+		if !held {
+			closeHeldMedia(media)
+			cleanup()
+		}
+	}()
 	if !s.requireCSRF(w, r) {
 		return
 	}
@@ -75,7 +83,7 @@ func (s *Server) handleCreatePost(w http.ResponseWriter, r *http.Request) {
 		root = threadRoot
 	}
 
-	images, newKeys, err := s.postImagesFromForm(r.Context(), r, post.ID, nil)
+	images, newKeys, media, err := s.postImagesFromForm(r.Context(), r, post.ID, nil)
 	if err != nil {
 		writePostImageRequestError(w, err)
 		return
@@ -93,7 +101,8 @@ func (s *Server) handleCreatePost(w http.ResponseWriter, r *http.Request) {
 	if root == nil {
 		root = post
 	}
-	s.publishPostCreated(post, root, user)
+	s.publishPostCreated(post, root, user, media, cleanup)
+	held = true
 	http.Redirect(
 		w,
 		r,
@@ -139,11 +148,12 @@ func (s *Server) handleEditPost(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 	previousImages := append([]store.PostImage(nil), post.Images...)
-	images, newKeys, err := s.postImagesFromForm(r.Context(), r, post.ID, previousImages)
+	images, newKeys, media, err := s.postImagesFromForm(r.Context(), r, post.ID, previousImages)
 	if err != nil {
 		writePostImageRequestError(w, err)
 		return
 	}
+	closeHeldMedia(media)
 	post.Body = truncateRunes(body, 12000)
 	post.Images = images
 	if err := s.store.UpdatePost(r.Context(), post); err != nil {