fix(uploads): graceful fallback for browser-unplayable video (HEVC .mov)

macOS screen recordings are HEVC inside a .mov container, which Chromium,
Firefox and stock Electron can't decode. The file uploaded fine and a
server-side ffmpeg poster was generated, but inline <video> playback failed
silently — stuck at 0:00 with no error, since AttachmentRenderer had no error
handling. Root cause: the system had no concept of web-playability.

Server detects, client degrades:
- mediaPlayable.ts: classifyVideoPlayable(mimetype, codec) — tri-state
  (false = known-undecodable e.g. HEVC/ProRes, true = web codec in web
  container, null = unknown/optimistic). Never widens `false` beyond codecs
  that fail everywhere, so ffmpeg-less instances keep prior behaviour.
- probeMediaMeta now captures the video codec_name; the upload finish hook
  stores the verdict in the new attachments.playable column (migration 0007).
- Flag propagated through every serializer: space messages, DMs, WS, and
  federation relay (outbound + inbound) — federation-compatible.
- VideoAttachment component: playable===false renders a download card (poster
  + "Can't play here — download" + name/duration/size) with no dead-player
  flash; otherwise plays inline with an onError fallback to the same card.

Specs updated: uploads.md, database.md, federation.md.

packages/server/src/routes/dm.ts

@@ -122,6 +122,7 @@ export function buildDmMessageWithUser(
       width: a.width ?? null,
       height: a.height ?? null,
       duration: a.duration ?? null,
+      playable: a.playable ?? null,
       federationStatus: a.federationStatus ?? null,
       federationMeta: a.federationMeta ?? null,
       createdAt: a.createdAt,

packages/server/src/routes/federation.ts

@@ -2911,6 +2911,7 @@ export async function federationRoutes(app: FastifyInstance): Promise<void> {
           width: a.width ?? undefined,
           height: a.height ?? undefined,
           duration: a.duration ?? undefined,
+          playable: a.playable ?? null,
           thumbnailFilename: a.thumbnailFilename ?? undefined,
           sourceUrl: `${localOrigin}/api/uploads/${a.filename}`,
         }));
@@ -3656,6 +3657,7 @@ async function processCreateEvent(
           width: attachment.width ?? null,
           height: attachment.height ?? null,
           duration: attachment.duration ?? null,
+          playable: attachment.playable ?? null,
           thumbnailFilename: null,  // Don't copy source thumbnail — it doesn't exist locally
           sourceUrl: attachment.sourceUrl,
           createdAt: now,
@@ -3830,6 +3832,7 @@ function processUpdateEvent(
       width: a.width,
       height: a.height,
       duration: a.duration,
+      playable: a.playable ?? null,
       createdAt: a.createdAt,
     }));
 

packages/server/src/routes/files.ts

@@ -20,6 +20,7 @@ import {
   generateVideoThumbnail,
   thumbFilename,
 } from '../utils/thumbnail.js';
+import { classifyVideoPlayable } from '../utils/mediaPlayable.js';
 import { eq } from 'drizzle-orm';
 import type { Attachment } from '@backspace/shared';
 import fs from 'node:fs';
@@ -251,6 +252,10 @@ export async function filesRoutes(app: FastifyInstance): Promise<void> {
       let width: number | null = null;
       let height: number | null = null;
       let duration: number | null = null;
+      // Tri-state web-playability for video (null = unknown/optimistic). Lets
+      // the client render a download fallback for codecs the browser can't
+      // decode (e.g. HEVC .mov) instead of a dead <video> stuck at 0:00.
+      let playable: boolean | null = null;
       try {
         if (isResizableImage(mimetype)) {
           stagedThumbName = await generateThumbnail(srcPath, mimetype, config.uploadDir);
@@ -271,6 +276,7 @@ export async function filesRoutes(app: FastifyInstance): Promise<void> {
             duration = mediaMeta.duration ?? null;
             if (width === null && mediaMeta.width) width = mediaMeta.width;
             if (height === null && mediaMeta.height) height = mediaMeta.height;
+            playable = classifyVideoPlayable(mimetype, mediaMeta.codec);
           }
         } else if (mimetype.startsWith('audio/')) {
           const mediaMeta = await probeMediaMeta(srcPath, mimetype);
@@ -286,7 +292,7 @@ export async function filesRoutes(app: FastifyInstance): Promise<void> {
           } catch { /* ignore */ }
           stagedThumbName = null;
         }
-        width = null; height = null; duration = null;
+        width = null; height = null; duration = null; playable = null;
       }
 
       // ── Commit point: rename .tus/<id> → uploads/<snowflakeId><ext> ──────
@@ -337,6 +343,7 @@ export async function filesRoutes(app: FastifyInstance): Promise<void> {
           width,
           height,
           duration,
+          playable,
           createdAt: now,
         }).run();
       } catch (err) {
@@ -362,6 +369,7 @@ export async function filesRoutes(app: FastifyInstance): Promise<void> {
         width: width ?? undefined,
         height: height ?? undefined,
         duration: duration ?? undefined,
+        playable,
         createdAt: now,
       };
 

packages/server/src/routes/messages.ts

@@ -118,6 +118,7 @@ export function fetchReplyToMessages(messages: (typeof schema.messages.$inferSel
         width: a.width ?? null,
         height: a.height ?? null,
         duration: a.duration ?? null,
+        playable: a.playable ?? null,
         createdAt: a.createdAt,
       })),
       embeds: [],
@@ -156,6 +157,7 @@ export function buildMessageWithUser(
       width: a.width ?? null,
       height: a.height ?? null,
       duration: a.duration ?? null,
+      playable: a.playable ?? null,
       federationStatus: a.federationStatus ?? null,
       federationMeta: a.federationMeta ?? null,
       createdAt: a.createdAt,