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.

bal/gui/qt/window.py

@@ -368,7 +368,6 @@ class BalWindow:
     def check_will(self):
         return Will.is_will_valid(
             self.willitems,
-            self.block_to_check,
             self.date_to_check,
             self.will_settings["baltx_fees"],
             self.window.wallet.get_utxos(),
@@ -459,9 +458,10 @@ class BalWindow:
         try:
             self.date_to_check = BalTimestamp(self.will_settings['threshold']).to_timestamp()
             # found = False
-            self.locktime_blocks = self.bal_plugin.LOCKTIME_BLOCKS.get()
-            self.current_block = Util.get_current_height(self.wallet.network)
-            self.block_to_check = 0
+            # NOTE: block-height tracking removed (A1) - locktimes are always
+            # UNIX timestamps now, so we no longer read the current block height
+            # or compute a block_to_check here. Validity is decided purely by
+            # comparing locktimes against date_to_check (a timestamp).
             self.no_willexecutor = self.bal_plugin.NO_WILLEXECUTOR.get()
             self.willexecutors = Willexecutors.get_willexecutors(
                 self.bal_plugin, update=True, bal_window=self, task=False
@@ -479,6 +479,10 @@ class BalWindow:
 
     def build_inheritance_transaction(self, ignore_duplicate=True, keep_original=True):
         try:
+            _logger.info(
+                "BAL-plugin \u25b8 STEP 1/7: prepare inheritance "
+                "(validate settings, amounts and locktime)"
+            )
             if self.disable_plugin:
                 _logger.info("plugin is disabled")
                 return
@@ -523,11 +527,26 @@ class BalWindow:
                     return
 
             try:
+                _logger.info(
+                    "BAL-plugin \u25b8 STEP 2/7: checking if the current will is "
+                    "still coherent (heirs, will-executors, fees, locktime)"
+                )
                 self.check_will()
+                _logger.info(
+                    "BAL-plugin \u25b8 STEP 2/7 result: will is COHERENT, "
+                    "nothing to rebuild"
+                )
             except WillExpiredException:
+                _logger.info(
+                    "BAL-plugin \u25b8 STEP 2/7 result: will EXPIRED -> "
+                    "invalidating on-chain (real fee)"
+                )
                 self.invalidate_will()
                 return
             except NoHeirsException:
+                _logger.info(
+                    "BAL-plugin \u25b8 STEP 2/7 result: no valid heirs -> abort"
+                )
                 return
             except WillPostponedException as e:
                 # The will was already signed/sent and is being postponed.
@@ -536,6 +555,10 @@ class BalWindow:
                 # can never be used by a will-executor), then press "Prepare"
                 # again
                 # to create the new postponed inheritance.
+                _logger.info(
+                    "BAL-plugin \u25b8 STEP 2/7 result: will POSTPONED on a "
+                    "signed/sent tx -> must invalidate on-chain first (real fee)"
+                )
                 _logger.info(f"will postponed: {e}")
                 self.show_message(
                     _(
@@ -553,6 +576,10 @@ class BalWindow:
                 self.invalidate_will()
                 return
             except NotCompleteWillException as e:
+                _logger.info(
+                    "BAL-plugin \u25b8 STEP 2/7 result: will NOT coherent -> "
+                    "REBUILD needed (no on-chain fee)"
+                )
                 _logger.info("{}:{}".format(type(e), e))
                 message = False
                 if isinstance(e, HeirChangeException):