Summon-RnD · snktshrma · Jun 16, 2026 · Jun 16, 2026
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -1,5 +1,14 @@
 # Changelog
 
+## Remove sample-data flash on load (2026-06-16)
+
+### Changed
+- App starts with an empty in-memory board and waits for `GET /api/board` before the first render.
+- Sample tasks moved to `src/data/sample-tasks.js` and used only when the server is unreachable (static `npx serve` mode).
+
+### Reasoning
+- Rendering built-in sample data first, then swapping in the DB board caused a visible flash on every refresh when running `python server.py`.
+
 ## SQLite persistence (2026-06-15)
 
 ### Added

diff --git a/README.md b/README.md
@@ -53,7 +53,8 @@ npm run test:watch
 | `index.html` | UI markup and styles |
 | `src/app/main.js` | Application logic (DOM, rendering, interactions) |
 | `src/data/constants.js` | Team roster, clients, sizes, colors |
-| `src/lib/board-sync.js` | Server load/save (non-blocking) |
+| `src/data/sample-tasks.js` | Demo tasks for static-only fallback |
+| `src/lib/board-sync.js` | Server load/save (first render after load) |
 | `server.py` | Flask app + SQLite API |
 | `tests/` | Vitest unit tests |
 

diff --git a/src/app/main.js b/src/app/main.js
@@ -15,6 +15,7 @@ import {
   normalizeProposal, mockTranscript, isoCap,
 } from "../lib/capture.js";
 import { startBoardSync } from "../lib/board-sync.js";
+import { buildSampleTasks } from "../data/sample-tasks.js";
 
 /* ================= sample data ================= */
 /* al = ASR aliases: common Whisper mishearings of each name.
@@ -25,82 +26,7 @@ const VOCAB_TEXT = buildVocabText();
 
 const { T, setUid, getUid } = createTaskFactory();
 
-const DATA = [
-  /* ---- Client pilot: Derichebourg (waste-sorting robot) ---- */
-  T("Derichebourg pilot — sorting robot","ia",{p:"high",d:"2026-07-10",open:true,c:[
-    T("Integrate RS03 drive motors","sk",{p:"high",d:"2026-06-16",s:"l",open:true,c:[
-      T("Mount RS03 motors and couplers","sk",{done:true,d:"2026-06-08",s:"m"}),
-      T("Wire motor CAN bus to controller","sk",{d:"2026-06-14",s:"m"}),
-      T("Calibrate RS03 torque limits","sk",{d:"2026-06-17",s:"s"}),
-    ]}),
-    T("Tune obstacle avoidance for the sorting line","ak",{p:"high",d:"2026-06-19",s:"l",open:true,c:[
-      T("Collect depth data along the conveyor","ak",{done:true,d:"2026-06-10",s:"m"}),
-      T("Train avoidance model","ak",{d:"2026-06-18",s:"l"}),
-      T("Field test near the conveyor","ak",{d:"2026-06-22",s:"m"}),
-    ]}),
-    T("Fix D-Wave board brownout under load","ly",{p:"high",d:"2026-06-12",s:"m",open:true,c:[
-      T("Diagnose the power regulator","ly",{done:true,d:"2026-06-11",s:"s"}),
-      T("Replace regulator and retest","ly",{d:"2026-06-13",s:"m"}),
-    ]}),
-    T("Approve motor procurement budget","jn",{d:"2026-06-15",s:"s"}),
-    T("Coordinate on-site pilot install","fd",{d:"2026-06-30",s:"l"}),
-  ]}),
-
-  /* ---- Client pilot: JCDecaux (billboard-servicing robot) ---- */
-  T("JCDecaux pilot — billboard servicing","ak",{p:"high",d:"2026-07-20",open:true,c:[
-    T("Design board-mount manipulator arm","ia",{d:"2026-06-23",s:"l",open:true,c:[
-      T("CAD the arm linkage","ia",{d:"2026-06-18",s:"m"}),
-      T("Source Feetech servos for the arm","lm",{d:"2026-06-20",s:"s"}),
-    ]}),
-    T("Autonomous navigation between billboards","ak",{p:"high",d:"2026-06-26",s:"xl",open:true,c:[
-      T("Build city route planner","ak",{d:"2026-06-24",s:"l"}),
-      T("GPS waypoint following","ak",{d:"2026-06-25",s:"m"}),
-    ]}),
-    T("Hub-motor sizing for outdoor terrain","sk",{d:"2026-06-20",s:"m"}),
-    T("Demo prep for JCDecaux","fd",{d:"2026-06-27",s:"s"}),
-  ]}),
-
-  /* ---- Client pilot: Onet (floor-cleaning autonomy) ---- */
-  T("Onet pilot — floor-cleaning autonomy","ak",{d:"2026-08-01",open:true,c:[
-    T("Map the Onet facility floorplan","ak",{d:"2026-06-21",s:"m"}),
-    T("Integrate Feetech servos for the brush arm","sk",{d:"2026-06-24",s:"m",open:true,c:[
-      T("Mount the brush assembly","lm",{d:"2026-06-22",s:"s"}),
-      T("Tune servo sweep pattern","sk",{d:"2026-06-25",s:"s"}),
-    ]}),
-    T("Safety e-stop wiring","ly",{p:"high",d:"2026-06-16",s:"s"}),
-  ]}),
-
-  /* ---- Internal R&D: core platform ---- */
-  T("RoboOS v2 — core platform","ia",{p:"high",d:"2026-07-31",open:true,c:[
-    T("Migrate OS to RS04 motor drivers","sk",{p:"high",d:"2026-06-24",s:"l",open:true,c:[
-      T("Port CAN driver to RS04","sk",{d:"2026-06-22",s:"m"}),
-      T("Bench-test RS04 closed loop","sk",{d:"2026-06-23",s:"m"}),
-    ]}),
-    T("Real-time locomotion controller","ak",{d:"2026-06-29",s:"l"}),
-    T("Evaluate EL05 actuators","sk",{d:"2026-06-17",s:"m",open:true,c:[
-      T("Run EL05 load tests","sk",{done:true,d:"2026-06-09",s:"s"}),
-      T("Compare EL05 vs RS02 efficiency","sk",{d:"2026-06-18",s:"s"}),
-    ]}),
-    T("Nightly build + hardware-in-the-loop rig","ia",{d:"2026-06-21",s:"m"}),
-    T("Assemble robot chassis v2","ia",{d:"2026-07-06",s:"l"}),
-  ]}),
-
-  /* ---- Client pilot: NSI (inventory-scanning robot) ---- */
-  T("NSI pilot — inventory scanning","ia",{d:"2026-07-15",open:true,c:[
-    T("Scoping follow-up with NSI","fd",{d:"2026-06-19",s:"s"}),
-    T("Barcode scanner integration","sk",{d:"2026-06-28",s:"m"}),
-    T("Aisle navigation tuning","ak",{d:"2026-07-02",s:"m"}),
-  ]}),
-];
-
-/* subtasks inherit their parent task's owner by default — with an occasional
-   (seeded-random) different owner sprinkled in, like a real team would have */
-{ let seed=7; const rnd=()=>(seed=(seed*1103515245+12345)%2147483648)/2147483648;
-  const keys=Object.keys(PEOPLE);
-  const walk=(nodes,parent,depth)=>nodes.forEach(n=>{
-    if(depth>=2&&parent) n.owner=rnd()<0.7?parent.owner:keys[Math.floor(rnd()*keys.length)];
-    walk(n.children,n,depth+1); });
-  walk(DATA,null,0); }
+const DATA = [];
 
 const findPath = (id, nodes = DATA, path = []) => findPathIn(id, nodes, path);
 const depthOf = (id) => depthOfIn(id, DATA);
@@ -1587,8 +1513,6 @@ function renderAll(){ renderFilter(); renderDash();
 }
 Object.defineProperty(window, "CAP", { get: () => CAP, configurable: true });
 
-renderAll();
-
 const _globals = {
   toggleSearch, openTeam, micFabTap, openTranscript, toggleSettings, toggleSidebar, closeSettings,
   toggleFlyout, toggleFocus, toggleShowDone, toggleSubs, closeCapture, toggleCapLang, minimizeCapture,
@@ -1607,4 +1531,5 @@ startBoardSync({
   setUid,
   renderAll,
   onReady: (save) => { requestSave = save; },
+  fallback: () => { DATA.splice(0, DATA.length, ...buildSampleTasks(T)); },
 });
diff --git a/src/data/sample-tasks.js b/src/data/sample-tasks.js
@@ -0,0 +1,77 @@
+import { PEOPLE } from "./constants.js";
+
+export function buildSampleTasks(T) {
+  const data = [
+    T("Derichebourg pilot - sorting robot", "ia", { p: "high", d: "2026-07-10", open: true, c: [
+      T("Integrate RS03 drive motors", "sk", { p: "high", d: "2026-06-16", s: "l", open: true, c: [
+        T("Mount RS03 motors and couplers", "sk", { done: true, d: "2026-06-08", s: "m" }),
+        T("Wire motor CAN bus to controller", "sk", { d: "2026-06-14", s: "m" }),
+        T("Calibrate RS03 torque limits", "sk", { d: "2026-06-17", s: "s" }),
+      ] }),
+      T("Tune obstacle avoidance for the sorting line", "ak", { p: "high", d: "2026-06-19", s: "l", open: true, c: [
+        T("Collect depth data along the conveyor", "ak", { done: true, d: "2026-06-10", s: "m" }),
+        T("Train avoidance model", "ak", { d: "2026-06-18", s: "l" }),
+        T("Field test near the conveyor", "ak", { d: "2026-06-22", s: "m" }),
+      ] }),
+      T("Fix D-Wave board brownout under load", "ly", { p: "high", d: "2026-06-12", s: "m", open: true, c: [
+        T("Diagnose the power regulator", "ly", { done: true, d: "2026-06-11", s: "s" }),
+        T("Replace regulator and retest", "ly", { d: "2026-06-13", s: "m" }),
+      ] }),
+      T("Approve motor procurement budget", "jn", { d: "2026-06-15", s: "s" }),
+      T("Coordinate on-site pilot install", "fd", { d: "2026-06-30", s: "l" }),
+    ] }),
+
+    T("JCDecaux pilot - billboard servicing", "ak", { p: "high", d: "2026-07-20", open: true, c: [
+      T("Design board-mount manipulator arm", "ia", { d: "2026-06-23", s: "l", open: true, c: [
+        T("CAD the arm linkage", "ia", { d: "2026-06-18", s: "m" }),
+        T("Source Feetech servos for the arm", "lm", { d: "2026-06-20", s: "s" }),
+      ] }),
+      T("Autonomous navigation between billboards", "ak", { p: "high", d: "2026-06-26", s: "xl", open: true, c: [
+        T("Build city route planner", "ak", { d: "2026-06-24", s: "l" }),
+        T("GPS waypoint following", "ak", { d: "2026-06-25", s: "m" }),
+      ] }),
+      T("Hub-motor sizing for outdoor terrain", "sk", { d: "2026-06-20", s: "m" }),
+      T("Demo prep for JCDecaux", "fd", { d: "2026-06-27", s: "s" }),
+    ] }),
+
+    T("Onet pilot - floor-cleaning autonomy", "ak", { d: "2026-08-01", open: true, c: [
+      T("Map the Onet facility floorplan", "ak", { d: "2026-06-21", s: "m" }),
+      T("Integrate Feetech servos for the brush arm", "sk", { d: "2026-06-24", s: "m", open: true, c: [
+        T("Mount the brush assembly", "lm", { d: "2026-06-22", s: "s" }),
+        T("Tune servo sweep pattern", "sk", { d: "2026-06-25", s: "s" }),
+      ] }),
+      T("Safety e-stop wiring", "ly", { p: "high", d: "2026-06-16", s: "s" }),
+    ] }),
+
+    T("RoboOS v2 - core platform", "ia", { p: "high", d: "2026-07-31", open: true, c: [
+      T("Migrate OS to RS04 motor drivers", "sk", { p: "high", d: "2026-06-24", s: "l", open: true, c: [
+        T("Port CAN driver to RS04", "sk", { d: "2026-06-22", s: "m" }),
+        T("Bench-test RS04 closed loop", "sk", { d: "2026-06-23", s: "m" }),
+      ] }),
+      T("Real-time locomotion controller", "ak", { d: "2026-06-29", s: "l" }),
+      T("Evaluate EL05 actuators", "sk", { d: "2026-06-17", s: "m", open: true, c: [
+        T("Run EL05 load tests", "sk", { done: true, d: "2026-06-09", s: "s" }),
+        T("Compare EL05 vs RS02 efficiency", "sk", { d: "2026-06-18", s: "s" }),
+      ] }),
+      T("Nightly build + hardware-in-the-loop rig", "ia", { d: "2026-06-21", s: "m" }),
+      T("Assemble robot chassis v2", "ia", { d: "2026-07-06", s: "l" }),
+    ] }),
+
+    T("NSI pilot - inventory scanning", "ia", { d: "2026-07-15", open: true, c: [
+      T("Scoping follow-up with NSI", "fd", { d: "2026-06-19", s: "s" }),
+      T("Barcode scanner integration", "sk", { d: "2026-06-28", s: "m" }),
+      T("Aisle navigation tuning", "ak", { d: "2026-07-02", s: "m" }),
+    ] }),
+  ];
+
+  let seed = 7;
+  const rnd = () => (seed = (seed * 1103515245 + 12345) % 2147483648) / 2147483648;
+  const keys = Object.keys(PEOPLE);
+  const walk = (nodes, parent, depth) => nodes.forEach((n) => {
+    if (depth >= 2 && parent) n.owner = rnd() < 0.7 ? parent.owner : keys[Math.floor(rnd() * keys.length)];
+    walk(n.children, n, depth + 1);
+  });
+  walk(data, null, 0);
+
+  return data;
+}
diff --git a/src/lib/board-sync.js b/src/lib/board-sync.js
@@ -55,7 +55,7 @@ export function applyBoard(board, data, setUid) {
   return true;
 }
 
-export function startBoardSync({ data, getUid, setUid, renderAll, onReady }) {
+export function startBoardSync({ data, getUid, setUid, renderAll, onReady, fallback }) {
   let boardReady = false;
   let saveTimer = null;
   let saveInFlight = false;
@@ -95,16 +95,18 @@ export function startBoardSync({ data, getUid, setUid, renderAll, onReady }) {
   }
 
   (async () => {
+    let loaded = false;
     try {
       const res = await fetch("/api/board");
       if (!res.ok) throw new Error("load failed");
-      if (applyBoard(await res.json(), data, setUid)) {
-        boardReady = true;
-        renderAll();
-      }
+      loaded = applyBoard(await res.json(), data, setUid);
+      if (!loaded) console.warn("Board from server rejected, using fallback data.");
     } catch (e) {
       console.warn("Board load skipped, using built-in sample data.", e);
     }
+    if (!loaded && fallback) fallback();
+    if (loaded) boardReady = true;
+    renderAll();
     onReady(scheduleSave);
   })();
 }
diff --git a/tests/board-sync.test.js b/tests/board-sync.test.js
@@ -0,0 +1,65 @@
+import { describe, expect, it, vi, beforeEach, afterEach } from "vitest";
+import { PEOPLE } from "../src/data/constants.js";
+import { createTaskFactory } from "../src/lib/tree.js";
+import { applyBoard, startBoardSync } from "../src/lib/board-sync.js";
+
+describe("board-sync", () => {
+  const { T, setUid } = createTaskFactory();
+
+  beforeEach(() => {
+    setUid(0);
+    Object.assign(PEOPLE, {
+      fd: { name: "Florian", initials: "FD", color: "#3b6ef6", role: "Lead", al: [] },
+    });
+  });
+
+  it("applyBoard replaces in-memory data from a server payload", () => {
+    const data = [];
+    const board = {
+      people: { fd: { name: "Florian", initials: "FD", color: "#3b6ef6", role: "Lead", al: [] } },
+      tasks: [T("Server project", "fd", { d: "2026-06-20", c: [T("Leaf", "fd", { d: "2026-06-18" })] })],
+      uid: 2,
+    };
+    expect(applyBoard(board, data, setUid)).toBe(true);
+    expect(data).toHaveLength(1);
+    expect(data[0].title).toBe("Server project");
+  });
+
+  it("startBoardSync renders once after loading from the server", async () => {
+    const data = [];
+    const renderAll = vi.fn();
+    const onReady = vi.fn();
+    const board = {
+      people: { fd: { name: "Florian", initials: "FD", color: "#3b6ef6", role: "Lead", al: [] } },
+      tasks: [T("DB project", "fd", { d: "2026-06-20", c: [T("Task", "fd", { d: "2026-06-18" })] })],
+      uid: 2,
+    };
+
+    vi.stubGlobal("fetch", vi.fn().mockResolvedValue({
+      ok: true,
+      json: async () => board,
+    }));
+
+    startBoardSync({ data, getUid: () => 0, setUid, renderAll, onReady, fallback: vi.fn() });
+    await vi.waitFor(() => expect(renderAll).toHaveBeenCalledTimes(1));
+    expect(data[0]?.title).toBe("DB project");
+    expect(onReady).toHaveBeenCalledOnce();
+
+    vi.unstubAllGlobals();
+  });
+
+  it("startBoardSync uses fallback when the server is unavailable", async () => {
+    const data = [];
+    const renderAll = vi.fn();
+    const fallback = vi.fn(() => { data.push(T("Fallback project", "fd", { d: "2026-06-20" })); });
+
+    vi.stubGlobal("fetch", vi.fn().mockRejectedValue(new Error("offline")));
+
+    startBoardSync({ data, getUid: () => 0, setUid, renderAll, onReady: () => {}, fallback });
+    await vi.waitFor(() => expect(renderAll).toHaveBeenCalledTimes(1));
+    expect(fallback).toHaveBeenCalledOnce();
+    expect(data[0]?.title).toBe("Fallback project");
+
+    vi.unstubAllGlobals();
+  });
+});