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/core/plugin_base.py

@@ -91,7 +91,7 @@ class BalPlugin(BasePlugin):
     """
 
     _version = None
-    __version__ = "0.3.3"  # AUTOMATICALLY GENERATED DO NOT EDIT
+    __version__ = "0.3.4"  # AUTOMATICALLY GENERATED DO NOT EDIT
 
     # Command used to open an .ics calendar file, per operating system.
     default_app = {
@@ -146,8 +146,17 @@ class BalPlugin(BasePlugin):
         self.ASK_BROADCAST = BalConfig(config, "bal_ask_broadcast", True)
         self.BROADCAST = BalConfig(config, "bal_broadcast", True)
         self.LOCKTIME_TIME = BalConfig(config, "bal_locktime_time", 90)
+        # NOTE (A1): block-height locktimes were removed; the plugin now uses
+        # only timestamp-based locktimes. LOCKTIME_BLOCKS is therefore no longer
+        # read anywhere in the code. It is kept here (dormant) on purpose, to
+        # avoid touching a persisted config key ("bal_locktime_blocks") that may
+        # already exist in some users' saved settings.
         self.LOCKTIME_BLOCKS = BalConfig(config, "bal_locktime_blocks", 144 * 90)
         self.LOCKTIMEDELTA_TIME = BalConfig(config, "bal_locktimedelta_time", 7)
+        # NOTE (A1): same as LOCKTIME_BLOCKS above - block-height locktimes were
+        # removed, so LOCKTIMEDELTA_BLOCKS is no longer read anywhere. It is kept
+        # here (dormant) on purpose, to avoid touching the persisted config key
+        # "bal_locktimedelta_blocks" that may already exist in saved settings.
         self.LOCKTIMEDELTA_BLOCKS = BalConfig(
             config, "bal_locktimedelta_blocks", 144 * 7
         )
@@ -158,6 +167,14 @@ class BalPlugin(BasePlugin):
         self.PREVIEW = BalConfig(config, "bal_preview", True)
         self.SAVE_TXS = BalConfig(config, "bal_save_txs", True)
 
+        # AUTO_SIGN (Group B / B2): when enabled, pressing "Check" will, after
+        # querying the will-executor servers, automatically sign the will
+        # transactions and broadcast them to their will-executors, without the
+        # user having to invoke "Sign" and "Broadcast" separately. The wallet
+        # password is requested only when the wallet is actually encrypted
+        # (handled by BalWindow.get_wallet_password). Default ON.
+        self.AUTO_SIGN = BalConfig(config, "bal_auto_sign", True)
+
         self.NO_WILLEXECUTOR = BalConfig(config, "bal_no_willexecutor", True)
         self.HIDE_REPLACED = BalConfig(config, "bal_hide_replaced", True)
         self.HIDE_INVALIDATED = BalConfig(config, "bal_hide_invalidated", True)