feat: add distributed-load icon and toolbar entry

AGENTS.md

@@ -24,6 +24,10 @@ Strict one-way MVVM + services: `views → viewmodels → services → core`.
 
 Runner emits OpenSeesPy commands in fixed order (`docs/architecture.md`): `wipe → model → node → fix → material → section → geomTransf → element → timeSeries → pattern/load → recorder → system/numberer/... → analyze`. Never reorder.
 
+## Branches
+
+- Do all feature/fix work on `develop` (or short-lived branches off `develop`, merged back into it). `main` is release-only — never commit directly to it.
+
 ## Verify (in this order)
 
 ```bash

src/otko/resources/icons-dark/assign-distributed.svg

@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" fill="none" stroke-linecap="round" stroke-linejoin="round">
+  <title>Assign distributed load</title>
+  <path d="M5 4.5h14" stroke="#F2A93B" stroke-width="1.6"/>
+  <path d="M7 4.5V14M12 4.5V14M17 4.5V14" stroke="#F2A93B" stroke-width="2"/>
+  <path d="M5 11.8l2 2.2 2-2.2M10 11.8l2 2.2 2-2.2M15 11.8l2 2.2 2-2.2" stroke="#F2A93B" stroke-width="2"/>
+  <path d="M4 18h16" stroke="#4F92E8" stroke-width="2"/>
+  <circle cx="7" cy="18" r="1.3" fill="#F2A93B"/>
+  <circle cx="12" cy="18" r="1.3" fill="#F2A93B"/>
+  <circle cx="17" cy="18" r="1.3" fill="#F2A93B"/>
+</svg>

src/otko/resources/icons/assign-distributed.svg

@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" fill="none" stroke-linecap="round" stroke-linejoin="round">
+  <title>Assign distributed load</title>
+  <path d="M5 4.5h14" stroke="#F2A93B" stroke-width="1.6"/>
+  <path d="M7 4.5V14M12 4.5V14M17 4.5V14" stroke="#F2A93B" stroke-width="2"/>
+  <path d="M5 11.8l2 2.2 2-2.2M10 11.8l2 2.2 2-2.2M15 11.8l2 2.2 2-2.2" stroke="#F2A93B" stroke-width="2"/>
+  <path d="M4 18h16" stroke="#4F92E8" stroke-width="2"/>
+  <circle cx="7" cy="18" r="1.3" fill="#F2A93B"/>
+  <circle cx="12" cy="18" r="1.3" fill="#F2A93B"/>
+  <circle cx="17" cy="18" r="1.3" fill="#F2A93B"/>
+</svg>

src/otko/views/menu_builder.py

@@ -315,6 +315,11 @@ class MenuBuilder:
                 "Assign Point Loads (Ctrl+L)",
                 "Assign point loads to the selected nodes.",
             ),
+            "_act_assign_distributed_load": (
+                "assign-distributed",
+                "Assign Distributed Loads…",
+                "Assign distributed loads to the selected frame elements.",
+            ),
             "_act_quick_guide": (
                 "quick-guide",
                 "Quick Guide",
@@ -541,6 +546,7 @@ class MenuBuilder:
         tb.addSeparator()
         tb.addAction(self._act_assign_support)
         tb.addAction(self._act_assign_load)
+        tb.addAction(self._act_assign_distributed_load)
 
     def _build_status_bar(self) -> None:
         self._status_label = QLabel("No project")