Add brewing section, plan chat, roaster learning, API tokens, Swagger docs, and full backup

Brewing:
- roasted_beans + brews tables; /beans (bean management with LLM URL
  prefill) and /brews (silhouette brewer picker across immersion/
  percolation/espresso, recipe fields, auto ratio, 0-10 rating, tasting
  notes); bean remaining weight derived from logged brew doses
- Green inventory lot form also prefills from a product URL

Navigation/UX:
- Side nav is now generated from one definition in nav.js, grouped
  Roasting / Brewing / account, consistent on every page

LLM:
- 'Ask the LLM' chat drawer on the planner (stateless /api/plan-chat)
  grounded in the plan, computed ledger, learned pace, and a new
  roaster-behavior profile aggregated from uploaded .alogs
  (/api/roaster-profile: TP lag, phase RoR, median milestone temps)
- The profile also feeds roast reviews and the planner curve's fallback
  milestone temps

API platform:
- User-generated bearer tokens (rpt_…) with account-page management;
  token requests skip CSRF; hand-authored OpenAPI 3 spec at
  /api/openapi.json rendered by self-hosted Swagger UI at /api-docs
- Full-database backup export/import (admin) + per-user data export

Co-Authored-By: Claude Fable 5 <[email protected]>

public/roasts.html

@@ -15,36 +15,7 @@
           <span class="brand-mark" aria-hidden="true">◐</span>
           <span class="brand-name">Roast Planner</span>
         </div>
-        <div class="nav-group">
-          <a class="nav-item" href="/app"
-            ><span class="nav-icon" aria-hidden="true">◐</span
-            ><span class="nav-label">Planner</span></a
-          >
-          <a class="nav-item" href="/account#your-plans"
-            ><span class="nav-icon" aria-hidden="true">▤</span
-            ><span class="nav-label">Plans</span></a
-          >
-          <a class="nav-item" href="/roasts" aria-current="page"
-            ><span class="nav-icon" aria-hidden="true">∿</span
-            ><span class="nav-label">Roasts</span></a
-          >
-          <a class="nav-item" href="/inventory"
-            ><span class="nav-icon" aria-hidden="true">▥</span
-            ><span class="nav-label">Inventory</span></a
-          >
-          <a class="nav-item" href="/cupping"
-            ><span class="nav-icon" aria-hidden="true">◒</span
-            ><span class="nav-label">Cupping</span></a
-          >
-          <a class="nav-item" href="/account"
-            ><span class="nav-icon" aria-hidden="true">◔</span
-            ><span class="nav-label">Account</span></a
-          >
-          <a class="nav-item hidden" id="nav-admin" href="/admin"
-            ><span class="nav-icon" aria-hidden="true">⚙</span
-            ><span class="nav-label">Admin</span></a
-          >
-        </div>
+        <div id="nav-links"></div>
         <div class="nav-spacer"></div>
         <button
           class="icon-btn nav-collapse-toggle"