feat(tabs): draw every lineage family, emphasize the selected tab's

Drawing only the selected tab's family hid every other connection until you
clicked into one. All families are drawn again (still as routed trees); the
selected tab's families (what it spawned, and the family it was spawned into)
get .lineage-family--focus: 2.5px instead of 1.5px, full opacity instead of
0.75, a larger end dot, and drawn last so nothing covers them.

Lanes follow strip order (cycling through CodemanLineage.MAX_LANES, 3), never
the selection, so a family's lines never move when you click a tab.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

src/web/public/index.html

@@ -2153,7 +2153,7 @@
                   <div class="set-row" id="appSettingsLineageLinesItem" data-search="lineage lines spawned worker parent connection">
                     <div class="set-row-text">
                       <span class="set-row-label">Spawn Lineage Lines <span class="set-tag">desktop</span></span>
-                      <span class="set-row-desc">For the selected tab, draw lines to the sessions it spawned and to the session that spawned it.</span>
+                      <span class="set-row-desc">Draw lines from each session to the sessions it spawned. The selected tab's family is drawn thicker.</span>
                     </div>
                     <label class="switch switch-sm"><input type="checkbox" id="appSettingsLineageLines" checked><span class="slider"></span></label>
                   </div>