Session 8: Fix broken prestige system - load prestige scripts, fix particles.js parse error, add prestige tab UI

dev-journal.md

@@ -181,3 +181,60 @@
 - Achievement progress tracking in stats panel
 - Consider adding more sound variations or background music
 - Potential new building tiers or prestige milestones
+
+---
+
+### Session 8 - 2026-08-21 (Afternoon)
+**Status:** ✅ Critical Bugfix - Prestige System Now Actually Loads (reported by user)
+
+#### Bug report:
+User reported (with screenshot) that clicking "Collect Stardust" no longer works
+after the prestige feature shipped in Session 5. Console showed:
+`Uncaught ReferenceError: PRESTIGE is not defined` (game.js line 159, in getClickPower)
+
+#### Root cause:
+Session 5 created `js/prestige.js` + `js/prestigeUI.js` and rewired `game.js` to
+call `PRESTIGE`/`PRESTIGE_UPGRADES` in click power, production, and offline
+earnings — but **never added the two script tags to `index.html`**. So:
+1. `PRESTIGE` was undefined → `getClickPower()` threw on every tick (250ms) and
+   every click → clicking did nothing, console flooded with errors.
+2. `Game.init()` calls `PrestigeUI.init()` → crashed the whole init sequence
+   after `UI.init()`, so even the harvest click listener was never attached.
+3. A second latent bug in `js/particles.js`: missing comma between
+   `createAmbientStars()` and `createPrestigeEffect()` (added in Session 5)
+   made the whole file fail to parse → `Particles` undefined → would have
+   broken `harvest()` even after fix #1.
+4. The prestige tab UI (essence display, prestige button, upgrade list) was
+   also never added to `index.html`.
+
+#### Fixes applied:
+- `index.html` - added `<script>` tags for `js/prestige.js` and `js/prestigeUI.js`
+  (before `main.js`), added the ✦ Prestige tab button + tab panel with
+  `prestige-btn`, `prestige-essence-count`, `prestige-multiplier`,
+  `prestige-next-essence`, `prestige-upgrades-list`
+- `js/particles.js` - added missing comma after `createAmbientStars()`
+- `js/ui.js` - `UI.update()` now also calls `PrestigeUI.update()` so the
+  prestige display refreshes every tick
+
+#### Verification:
+Built a headless DOM test harness (`headless-test/test_game.py`, lives OUTSIDE
+the game repo) running all game scripts in a real JS engine (py_mini_racer /
+JavaScriptCore) with DOM stubs. 33/33 checks pass: init, 5 harvest clicks →
+5 stardust, 20 game ticks without errors, full prestige flow (2M stardust →
+1 essence, reset, multiplier), prestige upgrade purchase math, UI rendering,
+firstPrestige achievement, save/load round-trip preserving essence.
+
+#### Files modified:
+- `index.html` - prestige scripts + prestige tab UI
+- `js/particles.js` - missing comma (parse error)
+- `js/ui.js` - PrestigeUI.update() wired into UI.update()
+
+#### Lessons / notes for future sessions:
+- Always check `index.html` script tags when adding new JS files!
+- A headless smoke test exists at /workspace/headless-test/test_game.py —
+  re-run it after any change to js/ to catch ReferenceErrors before pushing.
+  (Requires `pip install py_mini_racer`.)
+
+#### Next goals:
+- Achievement progress tracking in stats panel
+- Consider adding a "next essence at X stardust" progress hint

index.html

@@ -50,6 +50,7 @@
                     <button class="tab-btn active" data-tab="upgrades">Upgrades</button>
                     <button class="tab-btn" data-tab="achievements">Achievements</button>
                     <button class="tab-btn" data-tab="stats">Stats</button>
+                    <button class="tab-btn" data-tab="prestige">✦ Prestige</button>
                 </div>
 
                 <div id="upgrades-tab" class="tab-content active">
@@ -66,6 +67,33 @@
                     <h3>Statistics</h3>
                     <div id="stats-content"></div>
                 </div>
+
+                <div id="prestige-tab" class="tab-content">
+                    <h3>✦ Prestige</h3>
+                    <div id="prestige-info">
+                        <div class="prestige-essence">
+                            <span class="essence-icon">✦</span>
+                            <span id="prestige-essence-count">0</span>
+                            <span style="font-size:0.85rem; color:var(--text-secondary)">Stellar Essence</span>
+                        </div>
+                        <div class="prestige-multiplier">
+                            Production bonus: <span id="prestige-multiplier">+0%</span>
+                        </div>
+                        <div class="prestige-next">
+                            Next prestige: <span id="prestige-next-essence">0</span> ✦
+                        </div>
+                        <p style="font-size:0.8rem; color:var(--text-muted); margin:8px 0">
+                            Requires 1M total stardust for the first ✦. Prestige resets
+                            stardust, buildings and upgrades — but keeps essence and
+                            prestige upgrades.
+                        </p>
+                        <button id="prestige-btn" class="prestige-btn" disabled>
+                            ✦ Prestige
+                        </button>
+                    </div>
+                    <h3 style="margin-top:15px">Prestige Upgrades</h3>
+                    <div id="prestige-upgrades-list"></div>
+                </div>
             </aside>
         </div>
 
@@ -104,6 +132,8 @@
     <script src="js/stats.js"></script>
     <script src="js/particles.js"></script>
     <script src="js/audio.js"></script>
+    <script src="js/prestige.js"></script>
+    <script src="js/prestigeUI.js"></script>
     <script src="js/main.js"></script>
 </body>
 </html>

js/particles.js

@@ -177,7 +177,7 @@ const Particles = {
             
             document.getElementById('game-container').appendChild(star);
         }
-    }
+    },
     /**
      * Create prestige reset effect - cosmic explosion
      */

js/ui.js

@@ -35,6 +35,9 @@ const UI = {
         
         // Stats
         Stats.update();
+        
+        // Prestige
+        PrestigeUI.update();
     },
 
     /**