diff --git a/backend/scripts/migrate_phys9_tasks.cjs b/backend/scripts/migrate_phys9_tasks.cjs
new file mode 100644
index 0000000..cdad699
--- /dev/null
+++ b/backend/scripts/migrate_phys9_tasks.cjs
@@ -0,0 +1,94 @@
+// Inject task panels (ptab-pN scaffold + JS auto-render) into physics_9_ch4.html
+// for §31..§36 — the only paragraphs with TASKS_PN arrays in the monolith.
+'use strict';
+const fs = require('fs');
+const path = require('path');
+
+const TBOOKS = path.join(__dirname, '..', '..', 'frontend', 'textbooks');
+const SRC = path.join(TBOOKS, 'physics_9.html');
+const DST = path.join(TBOOKS, 'physics_9_ch4.html');
+
+const src = fs.readFileSync(SRC, 'utf8');
+let ch4 = fs.readFileSync(DST, 'utf8');
+
+// === Extract each ptab-pN block (N in 31..36) ===
+function clean(s) {
+  return s
+    .replace(/[\u{1F300}-\u{1F9FF}]|[\u{2600}-\u{27BF}]|[\u{1F000}-\u{1F2FF}]|[\u{FE0F}]/gu, '')
+    .replace(/<i\s+class="fa[s ][^"]*"[^>]*>\s*<\/i>/g, '')
+    .trim();
+}
+
+function extractPtab(n) {
+  const tag = `id="ptab-p${n}"`;
+  const i = src.indexOf(tag);
+  if (i < 0) return null;
+  // Откатываемся к открывающему div
+  const divStart = src.lastIndexOf('<div', i);
+  // Ищем следующий ptab или конец tab-tasks
+  let endTag = src.indexOf(`id="ptab-p${n+1}"`, i);
+  if (endTag < 0) endTag = src.indexOf(`id="ptab-hard"`, i);
+  if (endTag < 0) endTag = i + 2000;
+  // Закрывающий </div> непосредственно перед следующим ptab
+  let closingDiv = src.lastIndexOf('</div>', endTag);
+  if (closingDiv < divStart) closingDiv = endTag;
+  return src.slice(divStart, closingDiv + 6);
+}
+
+const PTABS = {};
+for (let n = 31; n <= 36; n++) {
+  const b = extractPtab(n);
+  if (b) PTABS[n] = clean(b);
+}
+console.log('Extracted ptabs:', Object.keys(PTABS).map(k => `p${k}:${PTABS[k].length}b`).join(' '));
+
+// === Inject ptab block + auto-render call into each build_pN in ch4 ===
+// Pattern: each build_pN ends with `box.innerHTML = html; renderMath(box); wireReadBtn('pN');`
+// We append the ptab HTML to the same box, then call window.goToTask('pN', 0) to start.
+
+for (let n = 31; n <= 36; n++) {
+  if (!PTABS[n]) continue;
+  const pid = 'p' + n;
+  // Escape for template literal
+  const esc = PTABS[n].replace(/\\/g, '\\\\').replace(/`/g, '\\`').replace(/\$\{/g, '\\${');
+
+  // Find build_pN function end
+  const fnRegex = new RegExp(
+    `(function\\s+build_${pid}\\(\\)\\s*\\{[\\s\\S]*?wireReadBtn\\('${pid}'\\);)\\s*\\}`,
+    'm'
+  );
+  const match = ch4.match(fnRegex);
+  if (!match) {
+    console.warn(`build_${pid}: not found`);
+    continue;
+  }
+
+  // Build new function body: append ptab HTML + setup call
+  const injectedBlock = `
+  // === Задачи §${n} — task panel (auto-injected from monolith) ===
+  const tasksBlock = document.createElement('div');
+  tasksBlock.className = 'wg';
+  tasksBlock.style.marginTop = '20px';
+  tasksBlock.innerHTML = '<div class="wg-header"><span class="wg-badge">Задачи</span><div class="wg-title">Тренажёр §${n}</div></div>' + \`${esc}\`;
+  box.appendChild(tasksBlock);
+  // Auto-render first task
+  setTimeout(() => {
+    try { if (typeof goToTask === 'function') goToTask('${pid}', 0); }
+    catch(e) { console.warn('${pid} goToTask:', e.message); }
+  }, 80);`;
+
+  const newBody = match[1] + injectedBlock + '\n}';
+  ch4 = ch4.replace(fnRegex, () => newBody);
+  console.log(`  build_${pid}: injected ptab (${esc.length} bytes)`);
+}
+
+fs.writeFileSync(DST, ch4);
+console.log('ch4 size:', ch4.length);
+
+// Sanity parse inline scripts
+const scripts = [...ch4.matchAll(/<script>([\s\S]*?)<\/script>/g)];
+for (const m of scripts) {
+  try { new Function(m[1]); }
+  catch(e) { console.error('JS PARSE FAIL:', e.message); process.exit(1); }
+}
+console.log('inline JS parses OK');
diff --git a/frontend/textbooks/physics_9_ch4.html b/frontend/textbooks/physics_9_ch4.html
index 33cd6ec..a334c58 100644
--- a/frontend/textbooks/physics_9_ch4.html
+++ b/frontend/textbooks/physics_9_ch4.html
@@ -1072,6 +1072,39 @@ function build_p31(){
   box.innerHTML = html;
   renderMath(box);
   wireReadBtn('p31');
+  // === Задачи §31 — task panel (auto-injected from monolith) ===
+  const tasksBlock = document.createElement('div');
+  tasksBlock.className = 'wg';
+  tasksBlock.style.marginTop = '20px';
+  tasksBlock.innerHTML = '<div class="wg-header"><span class="wg-badge">Задачи</span><div class="wg-title">Тренажёр §31</div></div>' + `<div id="ptab-p31">
+    <div class="score-bar">
+      <div class="chip chip-ok">&nbsp;<span id="okp31">0</span></div>
+      <div class="chip chip-tot"><span id="curp31">0</span>&nbsp;/&nbsp;<span id="maxp31">12</span></div>
+      <button class="btn btn-ghost" onclick="resetTasks('p31')" style="padding:6px 13px;font-size:.74rem"> Заново</button>
+    </div>
+    <div class="prog-wrap"><div class="prog-fill" id="progp31" style="width:0%"></div></div>
+    <div class="nav-dots" id="navDotsp31"></div>
+    <div id="taskAreap31"></div>
+    <div class="feedback" id="fbp31"></div>
+    <div style="display:flex;gap:10px;margin-top:10px;justify-content:flex-end">
+      <button class="btn btn-next" id="nextBtnp31" onclick="nextTask('p31')" style="display:none"> Следующая</button>
+    </div>
+    <div class="summary" id="sump31">
+      <h2>§31 — готово!</h2>
+      <div class="big-score" id="sumScorep31"></div>
+      <div class="sum-grade" id="sumGradep31"></div>
+      <div class="sum-btns">
+        <button class="btn btn-pri" onclick="resetTasks('p31')"> Ещё раз</button>
+        <button class="btn btn-ghost" onclick="setParaTab('p32')">→ §32</button>
+      </div>
+    </div>
+  </div>`;
+  box.appendChild(tasksBlock);
+  // Auto-render first task
+  setTimeout(() => {
+    try { if (typeof goToTask === 'function') goToTask('p31', 0); }
+    catch(e) { console.warn('p31 goToTask:', e.message); }
+  }, 80);
 }
 
 function build_p32(){
@@ -1265,6 +1298,39 @@ function build_p32(){
   box.innerHTML = html;
   renderMath(box);
   wireReadBtn('p32');
+  // === Задачи §32 — task panel (auto-injected from monolith) ===
+  const tasksBlock = document.createElement('div');
+  tasksBlock.className = 'wg';
+  tasksBlock.style.marginTop = '20px';
+  tasksBlock.innerHTML = '<div class="wg-header"><span class="wg-badge">Задачи</span><div class="wg-title">Тренажёр §32</div></div>' + `<div id="ptab-p32" style="display:none">
+    <div class="score-bar">
+      <div class="chip chip-ok">&nbsp;<span id="okp32">0</span></div>
+      <div class="chip chip-tot"><span id="curp32">0</span>&nbsp;/&nbsp;<span id="maxp32">12</span></div>
+      <button class="btn btn-ghost" onclick="resetTasks('p32')" style="padding:6px 13px;font-size:.74rem"> Заново</button>
+    </div>
+    <div class="prog-wrap"><div class="prog-fill" id="progp32" style="width:0%"></div></div>
+    <div class="nav-dots" id="navDotsp32"></div>
+    <div id="taskAreap32"></div>
+    <div class="feedback" id="fbp32"></div>
+    <div style="display:flex;gap:10px;margin-top:10px;justify-content:flex-end">
+      <button class="btn btn-next" id="nextBtnp32" onclick="nextTask('p32')" style="display:none"> Следующая</button>
+    </div>
+    <div class="summary" id="sump32">
+      <h2>§32 — готово!</h2>
+      <div class="big-score" id="sumScorep32"></div>
+      <div class="sum-grade" id="sumGradep32"></div>
+      <div class="sum-btns">
+        <button class="btn btn-pri" onclick="resetTasks('p32')"> Ещё раз</button>
+        <button class="btn btn-ghost" onclick="setParaTab('p33')">→ §33</button>
+      </div>
+    </div>
+  </div>`;
+  box.appendChild(tasksBlock);
+  // Auto-render first task
+  setTimeout(() => {
+    try { if (typeof goToTask === 'function') goToTask('p32', 0); }
+    catch(e) { console.warn('p32 goToTask:', e.message); }
+  }, 80);
 }
 
 function build_p33(){
@@ -1524,6 +1590,39 @@ function build_p33(){
   box.innerHTML = html;
   renderMath(box);
   wireReadBtn('p33');
+  // === Задачи §33 — task panel (auto-injected from monolith) ===
+  const tasksBlock = document.createElement('div');
+  tasksBlock.className = 'wg';
+  tasksBlock.style.marginTop = '20px';
+  tasksBlock.innerHTML = '<div class="wg-header"><span class="wg-badge">Задачи</span><div class="wg-title">Тренажёр §33</div></div>' + `<div id="ptab-p33" style="display:none">
+    <div class="score-bar">
+      <div class="chip chip-ok">&nbsp;<span id="okp33">0</span></div>
+      <div class="chip chip-tot"><span id="curp33">0</span>&nbsp;/&nbsp;<span id="maxp33">8</span></div>
+      <button class="btn btn-ghost" onclick="resetTasks('p33')" style="padding:6px 13px;font-size:.74rem"> Заново</button>
+    </div>
+    <div class="prog-wrap"><div class="prog-fill" id="progp33" style="width:0%"></div></div>
+    <div class="nav-dots" id="navDotsp33"></div>
+    <div id="taskAreap33"></div>
+    <div class="feedback" id="fbp33"></div>
+    <div style="display:flex;gap:10px;margin-top:10px;justify-content:flex-end">
+      <button class="btn btn-next" id="nextBtnp33" onclick="nextTask('p33')" style="display:none"> Следующая</button>
+    </div>
+    <div class="summary" id="sump33">
+      <h2>§33 — готово!</h2>
+      <div class="big-score" id="sumScorep33"></div>
+      <div class="sum-grade" id="sumGradep33"></div>
+      <div class="sum-btns">
+        <button class="btn btn-pri" onclick="resetTasks('p33')"> Ещё раз</button>
+        <button class="btn btn-ghost" onclick="setParaTab('p34')">→ §34</button>
+      </div>
+    </div>
+  </div>`;
+  box.appendChild(tasksBlock);
+  // Auto-render first task
+  setTimeout(() => {
+    try { if (typeof goToTask === 'function') goToTask('p33', 0); }
+    catch(e) { console.warn('p33 goToTask:', e.message); }
+  }, 80);
 }
 
 function build_p34(){
@@ -1811,6 +1910,39 @@ Eп₂ = <span id="ep2val" style="color:#7c3aed">1000</span> Дж
   box.innerHTML = html;
   renderMath(box);
   wireReadBtn('p34');
+  // === Задачи §34 — task panel (auto-injected from monolith) ===
+  const tasksBlock = document.createElement('div');
+  tasksBlock.className = 'wg';
+  tasksBlock.style.marginTop = '20px';
+  tasksBlock.innerHTML = '<div class="wg-header"><span class="wg-badge">Задачи</span><div class="wg-title">Тренажёр §34</div></div>' + `<div id="ptab-p34" style="display:none">
+    <div class="score-bar">
+      <div class="chip chip-ok">&nbsp;<span id="okp34">0</span></div>
+      <div class="chip chip-tot"><span id="curp34">0</span>&nbsp;/&nbsp;<span id="maxp34">9</span></div>
+      <button class="btn btn-ghost" onclick="resetTasks('p34')" style="padding:6px 13px;font-size:.74rem"> Заново</button>
+    </div>
+    <div class="prog-wrap"><div class="prog-fill" id="progp34" style="width:0%"></div></div>
+    <div class="nav-dots" id="navDotsp34"></div>
+    <div id="taskAreap34"></div>
+    <div class="feedback" id="fbp34"></div>
+    <div style="display:flex;gap:10px;margin-top:10px;justify-content:flex-end">
+      <button class="btn btn-next" id="nextBtnp34" onclick="nextTask('p34')" style="display:none"> Следующая</button>
+    </div>
+    <div class="summary" id="sump34">
+      <h2>§34 — готово!</h2>
+      <div class="big-score" id="sumScorep34"></div>
+      <div class="sum-grade" id="sumGradep34"></div>
+      <div class="sum-btns">
+        <button class="btn btn-pri" onclick="resetTasks('p34')"> Ещё раз</button>
+        <button class="btn btn-ghost" onclick="setParaTab('p35')">→ §35</button>
+      </div>
+    </div>
+  </div>`;
+  box.appendChild(tasksBlock);
+  // Auto-render first task
+  setTimeout(() => {
+    try { if (typeof goToTask === 'function') goToTask('p34', 0); }
+    catch(e) { console.warn('p34 goToTask:', e.message); }
+  }, 80);
 }
 
 function build_p35(){
@@ -1932,6 +2064,39 @@ function build_p35(){
   box.innerHTML = html;
   renderMath(box);
   wireReadBtn('p35');
+  // === Задачи §35 — task panel (auto-injected from monolith) ===
+  const tasksBlock = document.createElement('div');
+  tasksBlock.className = 'wg';
+  tasksBlock.style.marginTop = '20px';
+  tasksBlock.innerHTML = '<div class="wg-header"><span class="wg-badge">Задачи</span><div class="wg-title">Тренажёр §35</div></div>' + `<div id="ptab-p35" style="display:none">
+    <div class="score-bar">
+      <div class="chip chip-ok">&nbsp;<span id="okp35">0</span></div>
+      <div class="chip chip-tot"><span id="curp35">0</span>&nbsp;/&nbsp;<span id="maxp35">8</span></div>
+      <button class="btn btn-ghost" onclick="resetTasks('p35')" style="padding:6px 13px;font-size:.74rem"> Заново</button>
+    </div>
+    <div class="prog-wrap"><div class="prog-fill" id="progp35" style="width:0%"></div></div>
+    <div class="nav-dots" id="navDotsp35"></div>
+    <div id="taskAreap35"></div>
+    <div class="feedback" id="fbp35"></div>
+    <div style="display:flex;gap:10px;margin-top:10px;justify-content:flex-end">
+      <button class="btn btn-next" id="nextBtnp35" onclick="nextTask('p35')" style="display:none"> Следующая</button>
+    </div>
+    <div class="summary" id="sump35">
+      <h2>§35 — готово!</h2>
+      <div class="big-score" id="sumScorep35"></div>
+      <div class="sum-grade" id="sumGradep35"></div>
+      <div class="sum-btns">
+        <button class="btn btn-pri" onclick="resetTasks('p35')"> Ещё раз</button>
+        <button class="btn btn-ghost" onclick="setParaTab('p36')">→ §36</button>
+      </div>
+    </div>
+  </div>`;
+  box.appendChild(tasksBlock);
+  // Auto-render first task
+  setTimeout(() => {
+    try { if (typeof goToTask === 'function') goToTask('p35', 0); }
+    catch(e) { console.warn('p35 goToTask:', e.message); }
+  }, 80);
 }
 
 function build_p36(){
@@ -2083,6 +2248,39 @@ $\\dfrac{mv_0^2}{2} + 0 = 0 + mgh_{\\max}$</span></li>
   box.innerHTML = html;
   renderMath(box);
   wireReadBtn('p36');
+  // === Задачи §36 — task panel (auto-injected from monolith) ===
+  const tasksBlock = document.createElement('div');
+  tasksBlock.className = 'wg';
+  tasksBlock.style.marginTop = '20px';
+  tasksBlock.innerHTML = '<div class="wg-header"><span class="wg-badge">Задачи</span><div class="wg-title">Тренажёр §36</div></div>' + `<div id="ptab-p36" style="display:none">
+    <div class="score-bar">
+      <div class="chip chip-ok">&nbsp;<span id="okp36">0</span></div>
+      <div class="chip chip-tot"><span id="curp36">0</span>&nbsp;/&nbsp;<span id="maxp36">8</span></div>
+      <button class="btn btn-ghost" onclick="resetTasks('p36')" style="padding:6px 13px;font-size:.74rem"> Заново</button>
+    </div>
+    <div class="prog-wrap"><div class="prog-fill" id="progp36" style="width:0%"></div></div>
+    <div class="nav-dots" id="navDotsp36"></div>
+    <div id="taskAreap36"></div>
+    <div class="feedback" id="fbp36"></div>
+    <div style="display:flex;gap:10px;margin-top:10px;justify-content:flex-end">
+      <button class="btn btn-next" id="nextBtnp36" onclick="nextTask('p36')" style="display:none"> Следующая</button>
+    </div>
+    <div class="summary" id="sump36">
+      <h2>§36 — готово!</h2>
+      <div class="big-score" id="sumScorep36"></div>
+      <div class="sum-grade" id="sumGradep36"></div>
+      <div class="sum-btns">
+        <button class="btn btn-pri" onclick="resetTasks('p36')"> Ещё раз</button>
+        <button class="btn btn-ghost" onclick="setParaTab('hard')">→ Сложные</button>
+      </div>
+    </div>
+  </div>`;
+  box.appendChild(tasksBlock);
+  // Auto-render first task
+  setTimeout(() => {
+    try { if (typeof goToTask === 'function') goToTask('p36', 0); }
+    catch(e) { console.warn('p36 goToTask:', e.message); }
+  }, 80);
 }
 
 function build_final4(){