docs: add Gemini response — MC versioning architecture locked

docs/consultations/gemini-modpack-installer-versioning-2026-04-16.md

@@ -131,3 +131,73 @@ Thanks Gemini! This one is meaty but you've never let us down. 🔥❄️
 
 — Michael (The Wizard) + Claude (Chronicler #93)  
 *Fire + Arcane + Frost = Forever 🔥💜❄️*
+
+---
+
+## Gemini's Response (April 16, 2026)
+
+**Summary:** SemVer compatibility maintained, Java version function updated, live version caching via pg-boss cron, NextCloud fallback path strategy.
+
+### Key Answers
+
+**Q1: Version normalization** — Store exact string from APIs (`26.1.2` or `1.21.1`). Standard `semver` npm package handles sorting natively — no custom parser needed.
+
+**Q2: Paper API** — Will return `26.1.2` exactly. Version array shows the transition: `[..., "1.21.1", "1.21.4", "26.1", "26.1.1", "26.1.2"]`.
+
+**Q3: Java version mapping — THE FIX:**
+
+```javascript
+function javaVersionForMC(mcVersion) {
+  const major = parseInt(mcVersion.split('.')[0]);
+  
+  // The new 2026+ scheme
+  if (major >= 26) return 21; 
+  
+  // The legacy 1.x.x scheme
+  if (major === 1) {
+    const minor = parseInt(mcVersion.split('.')[1]);
+    if (minor >= 21) return 21;
+    if (minor >= 17 && minor <= 20) return 17;
+    if (minor <= 16) return 8; 
+  }
+  
+  return 21; // Ultimate Frostwall fallback
+}
+```
+
+**Q4: CurseForge and Modrinth** — Both will return `gameVersions: ["26.1", "26.1.2"]`. Cache `/tag/game_version` endpoint via pg-boss cron — new `26.x` numbers appear automatically.
+
+**Q5: NextCloud folder naming** — Use exact version string (`standard-mods/26.1.2/`). Arbiter checks exact patch first, falls back to base release:
+
+```javascript
+async function getNextCloudModStack(mcVersion) {
+  const exactPath = `standard-mods/${mcVersion}/`;
+  const baseRelease = mcVersion.split('.').slice(0, 2).join('.');
+  const fallbackPath = `standard-mods/${baseRelease}/`;
+
+  if (await webdav.exists(exactPath)) return exactPath;
+  if (await webdav.exists(fallbackPath)) return fallbackPath;
+  
+  throw new Error(`Mod stack missing for both ${exactPath} and ${fallbackPath}`);
+}
+```
+
+**Q6: Live version caching** — pg-boss cron at 3AM, hit Paper + Modrinth, sort with `semver.rsort()`, store in DB table. UI reads from DB — stays fast.
+
+### Gemini's Note
+> "This new calendar-based system actually makes database sorting infinitely easier than the old `1.x.x` vs snapshot naming chaos."
+
+---
+
+## Conclusion
+
+Architecture locked. Three changes needed in Code:
+
+1. Replace `javaVersionForMC()` with the new function above
+2. Replace hardcoded version lists with live DB-backed lookups (pg-boss cron populates)
+3. Update NextCloud mod stack lookup to use exact-then-fallback path strategy
+
+**Next Steps:**
+1. File REQ for Code with the above changes
+2. Rename `standard-mods/1.21.1/` → `standard-mods/26.1.2/` in NextCloud (mods are the same)
+3. Add `semver` to package.json if not already present