Bump version to 5.3.11

[xirvik]

• Mobile: light / dark / system theme (mobile: add a theme setting: light, dark, or follow the system #3136, @xombiemp) — new Theme setting; System follows the device's dark-mode live. The near-black accent is relabeled Contrast and resolves to near-white on the dark theme.
• Mobile: fix the empty torrent list on the direct XML-RPC mount (mobile: fix the empty torrent list on the direct XML-RPC mount, plus a round of fixes #3134, @xombiemp) — plus new torrents inserted at their sorted position, a toast for torrents added from another session/rss/automation, keyboard-dismiss-on-scroll across all fields, and label-edit commit/cancel fixes.
• Mobile: don't blank the torrent list when every torrent is labeled (mobile: don't blank the torrent list when the label panel is incomplete #3133, @xirvik) — the label panel's "no label" bucket is absent when nothing is unlabeled; guard the lookup.
• Mobile: log swallowed request failures to the console (mobile: log swallowed request failures to the console #3135, @xombiemp) — diagnostic breadcrumbs for the silent failures that hid the blank-list bugs.