feat(bal): Group A (timestamps + statuses + anticipate docs) and Group B (auto-sign) v0.3.4

Bump plugin version to 0.3.4 (manifest, __init__, plugin_base, VERSION).

GROUP A
- A1: remove block-height locktimes; the plugin now uses UNIX timestamps
  only. The NLOCKTIME_BLOCKHEIGHT_MAX guard is kept on purpose (it forces
  every locktime to be a timestamp). chk_locktime is now 2-arg; int_locktime
  and anticipate_locktime no longer accept blocks; RAW input only accepts d/y.
  Two now-dormant configs (LOCKTIME_BLOCKS, LOCKTIMEDELTA_BLOCKS) are kept with
  comments to avoid touching persisted keys.
- A2: rename PENDING -> MEMPOOL everywhere (label 'Mempool', yellow #ffce30);
  add new UPDATED status; ANTICIPATED & UPDATED keep VALID; documented
  set_status rules; backward-compat migration (old PENDING -> MEMPOOL).
- A3: clarify that anticipating to a future date only rebuilds (never
  invalidates), while only a past locktime invalidates (WillExpired). Code was
  already correct; only the comment and docs were fixed.

Colour follow-up: UPDATED lightened from #800080 to #b266b2 (more readable),
updated in theme.py, docs and the theme test.

GROUP B
- B1: verified the 'Create your will' button already opens the guided wizard
  (no code change needed).
- B2: new persisted AUTO_SIGN setting (default ON) with an 'Auto-sign on Check'
  checkbox in the settings dialog. When enabled, Check signs and broadcasts
  automatically; the wallet password is requested only for encrypted wallets.

B2 follow-up (fixes reported after testing):
- Remove the duplicate sign/broadcast cycle in lists.check(); build_will_task()
  already signs and broadcasts.
- Suppress the manual 'press Sign/Broadcast' hint and its popup when AUTO_SIGN
  is ON (kept when OFF).
- Make broadcast one-shot: removed the retry flag and the Exception('retry');
  failed will-executors stay PUSH_FAIL and are skipped (no endless retry).
  PUSHED transactions are already excluded from re-collection.

Docs: inheritance-options.md/.html and inheritance-flow.svg updated to v0.3.4.
Tests: 206 passing (new test_anticipate_manual_locktime, test_anticipate_past_locktime,
test_group_b_auto_sign; updated core/util, core/will_extra, gui/theme, gui/widgets).
CHANGELOG.md added with one numbered entry per task.

tests/test_gui_theme.py

@@ -33,7 +33,8 @@ def test_color_invalidated():
 
 
 def test_color_invalidated_overrides_lower():
-    item = FakeWillItem(INVALIDATED=True, PENDING=True, COMPLETE=True)
+    # PENDING was renamed to MEMPOOL (A2).
+    item = FakeWillItem(INVALIDATED=True, MEMPOOL=True, COMPLETE=True)
     assert status_color(item) == "#f87838"
 
 
@@ -41,12 +42,20 @@ def test_color_replaced():
     assert status_color(FakeWillItem(REPLACED=True)) == "#ff97e9"
 
 
+def test_color_updated():
+    # UPDATED is a new status (A2): light violet. It is checked after REPLACED
+    # but before CONFIRMED/MEMPOOL in the priority list. The original violet
+    # (#800080) was too dark to read, so it was lightened to #b266b2.
+    assert status_color(FakeWillItem(UPDATED=True)) == "#b266b2"
+
+
 def test_color_confirmed():
     assert status_color(FakeWillItem(CONFIRMED=True)) == "#bfbfbf"
 
 
-def test_color_pending():
-    assert status_color(FakeWillItem(PENDING=True)) == "#ffce30"
+def test_color_mempool():
+    # PENDING was renamed to MEMPOOL (A2); the colour (yellow) is unchanged.
+    assert status_color(FakeWillItem(MEMPOOL=True)) == "#ffce30"
 
 
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