0.5.6 — Risk Scenarios nav dropdown

The two scenario pages now live under a single top-level nav entry, Risk Scenarios, that opens to their two children: Interactive (the branching cards) and Statics (the LinkedIn post set). One entry in the bar, two destinations behind it — the campaign reads as one thing.

What changed

• New chain delta src/v0/v0.5/v0.5.2/ overriding shared/components/menu.js. <rm-menu> collapses a run of contiguous pages that share a group string into a hover/click dropdown; ungrouped pages stay flat. Shipped the IFD way — a new delta folder, never an edit to a shipped version's inputs. HEAD (top-level pages) layers it and gets the dropdown; frozen version snapshots layer only up to their own version and stay byte-identical.
• build.js — scenarios and statics carry group: "Risk Scenarios"; scenarios is relabelled Interactive. pageList emits the optional group field so the menu (and the host's runtime rm-manifest) can build the dropdown.
• Dropdown styles added to every top-level page's own stylesheet — including the new Agents page — with --bg2 / --greenBg fallbacks so the panel renders identically everywhere.

Notes

• Rebased on upstream 0.5.4 (library externalised to assets/library/) and 0.5.5 (LLM access surface + the new Agents page). All three are in: the nav now reads Partners · Risk Scenarios ▾ · Library · Agents · Dev.
• The dropdown is a top-level-page enhancement. Frozen version pages render the same pages flat (Interactive · Statics as plain links) — expected, since those snapshots are immutable.
• Frozen outputs re-pinned: per snapshot the only change is the inlined RM.data.pages line (relabel + group field), verified by diff.
• Smoke: menuOf no longer counts the group button as a section; new assertions cover the dropdown (two members, open/close) and confirm version pages stay flat, alongside the inherited Agents-page assertions.