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.

bal/core/willexecutors.py

@@ -30,6 +30,14 @@ from .plugin_base import BalPlugin
 # block the UI.
 DEFAULT_TIMEOUT = 5
 
+# Single, shared wall-clock deadline (seconds) for ALL network waits the user
+# can watch in the GUI: the parallel broadcast (pushtxs), the parallel check
+# (searchtx), the will-executor ping and the will-executor list download.
+# Having ONE constant (instead of several scattered 30s/45s values) keeps the
+# experience consistent and makes it trivial to tune. Requested by the user
+# (reduced from 30s/45s to 20s, unified into one variable).
+NETWORK_DEADLINE = 20
+
 # Broadcast (pushtxs) timeouts.  Broadcasting a will is important, so we keep a
 # couple of quick retries to survive a transient hiccup -- but far from the old
 # 10s x 10 retries + 30s sleeps (~140s) that froze the wizard on a dead server.
@@ -43,7 +51,8 @@ PUSH_RETRY_SLEEP = 1
 # Global wall-clock deadline (seconds) for the whole parallel broadcast.  Once
 # it elapses we stop waiting for the still-pending servers, mark them as
 # "Timeout" and let the wizard proceed instead of appearing stuck.
-PUSH_GLOBAL_DEADLINE = 30
+# Derived from the single shared NETWORK_DEADLINE constant above.
+PUSH_GLOBAL_DEADLINE = NETWORK_DEADLINE
 
 # Check (searchtx) timeouts.  Used when the user presses "Check" to verify that
 # each will-executor still holds the transaction.  Like the broadcast path, the
@@ -53,7 +62,8 @@ PUSH_GLOBAL_DEADLINE = 30
 CHECK_TIMEOUT = 8
 CHECK_MAX_RETRIES = 1
 CHECK_RETRY_SLEEP = 1
-CHECK_GLOBAL_DEADLINE = 30
+# Derived from the single shared NETWORK_DEADLINE constant above.
+CHECK_GLOBAL_DEADLINE = NETWORK_DEADLINE
 
 _logger = get_logger(__name__)
 
@@ -68,6 +78,7 @@ class Willexecutors:
     # importing module-level names.  Single source of truth: the module
     # constants defined above.
     DEFAULT_TIMEOUT = DEFAULT_TIMEOUT
+    NETWORK_DEADLINE = NETWORK_DEADLINE
     PUSH_TIMEOUT = PUSH_TIMEOUT
     PUSH_MAX_RETRIES = PUSH_MAX_RETRIES
     PUSH_RETRY_SLEEP = PUSH_RETRY_SLEEP