feat(notes): render macroplan code blocks as a delivery plan grid

Follows the tikz pattern: the fence emits a base64 placeholder, then
the post-render hook lazily imports the parser and grid (separate
chunks) and mounts the grid only when a placeholder exists. Mono font
forced on the block because the flag-stacking math assumes Fira Code.

src/modules/macroplan/runMacroplan.spec.ts

@@ -0,0 +1,40 @@
+import { describe, expect, it } from "vitest"
+
+import { encodeUTF8ToBase64 } from "@/utils/decodeBase64ToUTF8"
+
+import { runMacroplan } from "./runMacroplan"
+
+const placeholder = (source: string): HTMLElement => {
+  const el = document.createElement("div")
+  el.className = "macroplan-block"
+  el.dataset.macroplanSource = encodeUTF8ToBase64(source)
+  document.body.appendChild(el)
+  return el
+}
+
+describe("runMacroplan", () => {
+  it("mounts the grid onto a valid placeholder", async () => {
+    const el = placeholder(
+      'title = "Plan"\n\n[[feature]]\nname = "Auth"\nstart = 2026-06-01\noriginal = 2026-06-15\n'
+    )
+
+    await runMacroplan(".macroplan-block")
+
+    expect(el.dataset.macroplanRendered).toBe("true")
+    expect(el.querySelector(".macroplan")).not.toBeNull()
+    expect(el.textContent).toContain("Auth")
+    el.remove()
+  })
+
+  it("renders the parse error inline for malformed sources", async () => {
+    const el = placeholder('[[feature]]\nname = "No dates"')
+
+    await runMacroplan(".macroplan-block")
+
+    expect(el.dataset.macroplanRendered).toBe("error")
+    expect(el.querySelector(".macroplan-error")?.textContent).toContain(
+      "missing `start`"
+    )
+    el.remove()
+  })
+})

src/modules/macroplan/runMacroplan.ts

@@ -0,0 +1,55 @@
+import { createApp } from "vue"
+
+import { decodeBase64ToUTF8 } from "@/utils/decodeBase64ToUTF8"
+
+const renderMacroplanError = (el: HTMLElement, err: unknown): void => {
+  const msg = err instanceof Error ? err.message : String(err)
+  el.textContent = ""
+  const box = document.createElement("div")
+  box.className = "macroplan-error"
+  const title = document.createElement("strong")
+  title.textContent = "Macroplan error"
+  const detail = document.createElement("pre")
+  detail.textContent = msg
+  box.append(title, detail)
+  el.appendChild(box)
+}
+
+/**
+ * Mount a MacroplanGrid onto every ```macroplan placeholder in scope.
+ * The parser (smol-toml + valibot) and the grid component only load
+ * when a placeholder actually exists, so notes without a plan pay nothing.
+ */
+export const runMacroplan = async (querySelector: string): Promise<void> => {
+  const elements = Array.from(
+    document.querySelectorAll<HTMLElement>(querySelector)
+  ).filter((el) => !el.dataset.macroplanRendered)
+  if (elements.length === 0) return
+
+  const [{ parseMacroplan }, { buildPlan }, { default: MacroplanGrid }] =
+    await Promise.all([
+      import("./model/parse"),
+      import("./model/plan"),
+      import("./components/MacroplanGrid.vue")
+    ])
+
+  for (const el of elements) {
+    el.dataset.macroplanRendered = "pending"
+
+    const encoded = el.dataset.macroplanSource
+    if (!encoded) {
+      el.dataset.macroplanRendered = "error"
+      continue
+    }
+
+    try {
+      const plan = buildPlan(parseMacroplan(decodeBase64ToUTF8(encoded)))
+      el.textContent = ""
+      createApp(MacroplanGrid, { plan }).mount(el)
+      el.dataset.macroplanRendered = "true"
+    } catch (err) {
+      renderMacroplanError(el, err)
+      el.dataset.macroplanRendered = "error"
+    }
+  }
+}