Track food eaten by weight in grams

Logging a meal now opens the dialog (like weigh-ins) with an optional
Amount (g) field; existing meals can get an amount via the edit dialog,
where clearing the field drops it. The overview's Meals tile shows the
day's total grams, and the weekly card gains a Food (grams) chart with
a self-scaling axis that stays hidden until any meal has an amount.

Events carry a new grams field (REAL column, auto-migrated); addEvent's
growing optional parameters are folded into an options object.

src/index.html

@@ -128,6 +128,7 @@
           <div class="stat">
             <div class="stat-label">Meals</div>
             <div class="stat-value" id="stat-meals">0</div>
+            <div class="stat-sub" id="stat-meals-grams" hidden></div>
           </div>
           <div class="stat">
             <div class="stat-label">Pees</div>
@@ -189,6 +190,10 @@
             <span class="lg eat"><span class="sw"></span>Meals</span>
           </div>
         </div>
+        <div class="chart" id="grams-chart-wrap" hidden>
+          <div class="chart-title">Food (grams)</div>
+          <svg id="chart-grams" class="chart-svg" viewBox="0 0 320 160" role="img" aria-label="Grams of food eaten per day for the last 7 days"></svg>
+        </div>
       </section>
 
       <section class="patterns" data-panel="sleep-timeline">
@@ -320,6 +325,9 @@
         <label id="note-weight-field" hidden>Weight (kg)
           <input type="number" id="note-weight" inputmode="decimal" step="0.01" min="0" placeholder="e.g. 5.2" />
         </label>
+        <label id="note-grams-field" hidden>Amount (g)
+          <input type="number" id="note-grams" inputmode="numeric" step="1" min="0" placeholder="e.g. 80 — leave empty if unknown" />
+        </label>
         <label>Note
           <textarea id="note-input" rows="4" placeholder="e.g. pee was instant, poo took 5min, ate 300g raw food"></textarea>
         </label>
@@ -348,6 +356,9 @@
         <label id="edit-weight-field" hidden>Weight (kg)
           <input type="number" id="edit-weight" inputmode="decimal" step="0.01" min="0" />
         </label>
+        <label id="edit-grams-field" hidden>Amount (g)
+          <input type="number" id="edit-grams" inputmode="numeric" step="1" min="0" />
+        </label>
         <label>Note
           <textarea id="edit-note" rows="4"></textarea>
         </label>