feat(v0.4.7): report area 500px, heirs one-per-line, wizard line breaks, ALL-DUST guard

Owner-approved changes after testing v0.4.6, plus accumulated v0.4.x work,
task-tracking notes, and an updated project HANDOFF document.

The four v0.4.7 changes:

1. Report area (BalBuildWillDialog) opens 500px tall (min) up to 700px (max),
   then the scrollbar takes over. Previously it opened ~140px (too short).

2. Heirs are listed ONE per line again (green, bold) in _build_success_report,
   reverting the v0.4.6 single-line form. Heir names can be long and the report
   now scrolls, so compression is no longer needed.

3. Two wizard texts get an explicit line break: after "(or backup)" in the date
   hint and after "miner fees" in the fee note (widgets.py).

4. ALL-DUST guard: when EVERY heir's share is below the Bitcoin dust limit, the
   inheritance would pay nobody. Heirs.prepare_lists now raises
   HeirAmountIsDustException at the end (where all heirs across all locktimes
   are known with their final dust state), and dialogs.task_phase1 shows a clear
   RED message and stops without building/signing/checking. A mix of dust +
   valid heirs keeps building normally. The guard is intentionally in
   prepare_lists, NOT prepare_transactions (which only sees the lowest locktime
   and would false-positive). HeirAmountIsDustException is imported in common.py.

Tests: 3 new tests in test_core_heirs_extra.py pin the dust behaviour (all-dust
raises; mixed continues; multi-locktime continues). Full suite: 258 passed.
ruff: no new errors. Version bumped 0.4.6 -> 0.4.7 (4 files). CHANGELOG #23.

Also adds/updates HANDOFF.md so any future AI (Claude or another model) can
resume the project with full context (rules, layout, build/test/lint, dust
logic, git flow), and records the task-tracking notes in
.agent_memory_tasks.md.

tests/test_group_f_heir_change_rebuild.py

@@ -0,0 +1,116 @@
+"""
+Tests for Group F (heir-change full rebuild, "Option A").
+
+Context (bugs E/F/K): when an heir was deleted/changed and the rebuilt
+inheritance transaction happened to keep the SAME txid, ``Will.update_will``
+used to REUSE the old (already signed/COMPLETE) WillItem, copying only the new
+heirs onto it. The downstream ``have_to_sign`` check then saw the item as
+COMPLETE and reported "Nothing to do", so the new will was never signed or
+broadcast.
+
+The fix reuses the old item ONLY when the real heirs are identical. These tests
+pin the behaviour of the helper ``Will._same_heirs`` that drives that decision.
+
+Run:
+    source electrum/env/bin/activate
+    python3 tests/test_group_f_heir_change_rebuild.py
+"""
+
+import sys
+import os
+sys.path.insert(0, os.path.join(os.path.dirname(__file__), os.pardir))
+
+from bal.core.will import Will
+
+
+# Heir entry layout (see heirs.py): [0]=address, [1]=amount, [2]=locktime.
+# Extra trailing fields (e.g. real/dust amount) must NOT affect equality.
+def _heir(address, amount, locktime, *extra):
+    return [address, amount, locktime, *extra]
+
+
+def test_same_heirs_identical():
+    """Identical real heirs -> True (old signed item may be reused)."""
+    a = {"alice": _heir("bc1qalice", "50%", "2026-12-01")}
+    b = {"alice": _heir("bc1qalice", "50%", "2026-12-01")}
+    assert Will._same_heirs(a, b) is True
+
+
+def test_same_heirs_ignores_extra_fields():
+    """Derived/extra fields (real amount, dust flag) do not break equality."""
+    a = {"alice": _heir("bc1qalice", "50%", "2026-12-01", 12345, "DUST")}
+    b = {"alice": _heir("bc1qalice", "50%", "2026-12-01")}
+    assert Will._same_heirs(a, b) is True
+
+
+def test_same_heirs_deleted_heir():
+    """Deleting one of two heirs -> changed -> False (must rebuild/re-sign)."""
+    old = {
+        "alice": _heir("bc1qalice", "50%", "2026-12-01"),
+        "bob": _heir("bc1qbob", "50%", "2026-12-01"),
+    }
+    new = {
+        # bob removed; alice is auto-scaled to 100% by the plugin.
+        "alice": _heir("bc1qalice", "100%", "2026-12-01"),
+    }
+    assert Will._same_heirs(old, new) is False
+
+
+def test_same_heirs_added_heir():
+    """Adding a heir -> changed -> False."""
+    old = {"alice": _heir("bc1qalice", "100%", "2026-12-01")}
+    new = {
+        "alice": _heir("bc1qalice", "50%", "2026-12-01"),
+        "carol": _heir("bc1qcarol", "50%", "2026-12-01"),
+    }
+    assert Will._same_heirs(old, new) is False
+
+
+def test_same_heirs_changed_amount():
+    """Same heir name but different amount -> changed -> False."""
+    old = {"alice": _heir("bc1qalice", "50%", "2026-12-01")}
+    new = {"alice": _heir("bc1qalice", "70%", "2026-12-01")}
+    assert Will._same_heirs(old, new) is False
+
+
+def test_same_heirs_changed_address():
+    """Same heir name but different destination address -> False."""
+    old = {"alice": _heir("bc1qalice", "50%", "2026-12-01")}
+    new = {"alice": _heir("bc1qOTHER", "50%", "2026-12-01")}
+    assert Will._same_heirs(old, new) is False
+
+
+def test_same_heirs_changed_locktime():
+    """Same heir but different delivery locktime -> False."""
+    old = {"alice": _heir("bc1qalice", "50%", "2026-12-01")}
+    new = {"alice": _heir("bc1qalice", "50%", "2027-06-01")}
+    assert Will._same_heirs(old, new) is False
+
+
+def test_same_heirs_ignores_willexecutor_pseudo_heirs():
+    """Reserved 'w!ll3x3c\"' pseudo-heirs are bookkeeping, not real heirs.
+
+    A difference only in the pseudo-heir entries must NOT be reported as a heir
+    change (the will-executor is refreshed separately in update_will).
+    """
+    old = {
+        "alice": _heir("bc1qalice", "100%", "2026-12-01"),
+        'w!ll3x3c"server1': _heir("bc1qwe1", "0", "0"),
+    }
+    new = {
+        "alice": _heir("bc1qalice", "100%", "2026-12-01"),
+        'w!ll3x3c"server2': _heir("bc1qwe2", "0", "0"),
+    }
+    assert Will._same_heirs(old, new) is True
+
+
+def test_same_heirs_empty():
+    """Two empty heir maps are equal; None is treated as empty."""
+    assert Will._same_heirs({}, {}) is True
+    assert Will._same_heirs(None, {}) is True
+    assert Will._same_heirs(None, None) is True
+
+
+if __name__ == "__main__":
+    import pytest
+    raise SystemExit(pytest.main([__file__, "-v"]))