attachments sync: attach offline, upload when linked, removals stick (#5168)

Desktop could not create an attachment at all, and a removed attachment or
dismissed preview came back on the next pull. Now:

- core: add_attachment keeps the bytes in the blob store and queues the row
  (schema v10: attachments.uploaded / upload_error). Push uploads it once its
  note has landed. A refusal that retrying won't fix (too large, id clash, hash
  mismatch) is recorded on the file and not re-sent every cycle; the editor
  shows it.
- core: removing a synced attachment or dismissing a preview leaves a tombstone
  in pending_deletes; push sends it as an `attachment`/`preview` delete, and a
  pull while it waits doesn't put the row back. A pull also keeps files still
  waiting to upload instead of replacing them wholesale.
- server: PUT /api/sync/attachments/<id> (raw body, sha256-checked, idempotent,
  size-capped) and child deletes in push, which apply regardless of LWW and
  answer noop for rows the caller can't see. One store_attachment helper for
  the upload route, the importer and sync. Protocol 5, feature attachment_sync;
  the client sends neither to a server without it.
- server: migration 0031 makes a link preview's insert/delete bump its note, so
  background-fetched previews and web dismissals reach linked devices.
- desktop: Attach and paste-image work offline (raw-bytes IPC command).
- SVG is served as a download by the desktop blob scheme too (as #1981 did for
  the web), and drawn as a file chip on both.
- autosync: drop the catch_unwind; release builds abort on panic, so it only
  ever worked in debug builds.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

android/ffi/src/models.rs

@@ -167,6 +167,8 @@ pub struct Attachment {
     pub mime: String,
     pub size: Option<i64>,
     pub sha256: Option<String>,
+    /// Why the server refused a file attached on this device. None otherwise.
+    pub upload_error: Option<String>,
 }
 
 #[derive(Debug, Clone, uniffi::Record)]
@@ -264,6 +266,7 @@ impl From<core_models::Attachment> for Attachment {
             mime,
             size,
             sha256,
+            upload_error,
         } = value;
         Attachment {
             id,
@@ -272,6 +275,7 @@ impl From<core_models::Attachment> for Attachment {
             mime,
             size,
             sha256,
+            upload_error,
         }
     }
 }
@@ -637,6 +641,10 @@ pub struct PushSummary {
     /// realistic case). Silently retrying forever would be the wrong shape.
     pub rejected: u64,
     pub errors: Vec<String>,
+    /// Files attached on this device that reached the server this cycle.
+    pub uploaded: u64,
+    /// Files that didn't; their reasons are in `errors`.
+    pub upload_failed: u64,
 }
 
 #[derive(Debug, Clone, uniffi::Record)]
@@ -668,6 +676,8 @@ impl From<core_push::PushSummary> for PushSummary {
             noop,
             rejected,
             errors,
+            uploaded,
+            upload_failed,
         } = value;
         PushSummary {
             batches: batches as u64,
@@ -678,6 +688,8 @@ impl From<core_push::PushSummary> for PushSummary {
             noop: noop as u64,
             rejected: rejected as u64,
             errors,
+            uploaded: uploaded as u64,
+            upload_failed: upload_failed as u64,
         }
     }
 }