UI polish and signed-tx colour fix (v0.3.3)

Fix and refine the BAL plugin GUI without changing business logic:

core/will.py: restore the PUSHED requirement in needs_server_check so a
signed-but-not-broadcast will is no longer server-queried and therefore
stays blue (COMPLETE) instead of turning red (CHECK_FAIL). This matches the
original Gitea check() condition.

gui/qt/widgets.py: WillSettingsWidget vertical layout now caps every row to
the widest date-row width and left-aligns them; the leading icons keep their
original HelpButton width.

gui/qt/lists.py + gui/qt/common.py: the wizard toolbar button now shows a
28x28 icon plus a bold 'Create your will' caption (QSize imported).

gui/qt/dialogs.py (BalBuildWillDialog):
- closing summary row labelled 'All done: Ok' with a blank separator above it;
- 'checking variables' capitalised to 'Checking variables' (redundant trailing
  colon dropped);
- final auto-closing countdown replaced by an explicit right-aligned 'Close'
  button; intermediate technical pauses kept; next-steps popup preserved.

gui/qt/window.py + core/plugin_base.py: guide show_message on build, and
sync_hide_filters() in update_all so hide flags refresh immediately.

tests: test_needs_server_check updated; added offscreen preview helpers.
Version bumped to 0.3.3. 186 tests pass; ruff clean (baseline only).

bal/manifest.json

@@ -1,7 +1,7 @@
 {
     "name": "bal",
     "fullname": "Bitcoin After Life",
-    "version": "0.3.2",
+    "version": "0.3.3",
     "description": "Provides free and decentralized Bitcoin inheritance support. Build time-locked 'will' transactions that transfer funds to your heirs if you stop refreshing them (dead-man's switch), optionally relayed by will-executor servers.",
     "author": "Svatantrya",
     "licence": "MIT",