feat: inverter model dropdown on settings page

Replace the free-text inverter model input with a dropdown populated from
the driver registry, so only real, supported models can be selected (no
typos or garbage values).

- settings.py: derive inverter_model options from the driver registry
  (single source of truth) via a lazy _inverter_model_options() helper,
  with a static fallback if the registry can't be imported.
- index.html: swap the text input for a <select> and populate it from the
  API's options list, preserving the currently-configured model.

This also fixes the drift where the hardcoded options list was missing the
5 new drivers (lxp_6k/12k/18k, fortress_envy_12k, bigbattery_sna_6k).

Author: jmewing

api/static/index.html

@@ -392,7 +392,7 @@ <h3>Timer Schedule</h3>
             <div class="field"><label>Dongle Port</label><input type="number" data-key="dongle_port" placeholder="8000"></div>
             <div class="field"><label>Datalog Serial</label><input type="text" data-key="datalog_serial" placeholder="BJxxxxxxxx"></div>
             <div class="field"><label>Inverter Serial</label><input type="text" data-key="inverter_serial" placeholder="5xxxxxxxx"></div>
-            <div class="field"><label>Inverter Model</label><input type="text" data-key="inverter_model" placeholder="eg4_6000xp"></div>
+            <div class="field"><label>Inverter Model</label><select data-key="inverter_model" id="inverter-model-select"></select></div>
           </div>
         </div></div>
         <div class="card" style="margin-top:1em;"><div class="card-section"><h3>Limits & Preferences</h3>
@@ -1030,6 +1030,9 @@ <h4 style="margin-bottom:0.5rem;">${g.title}</h4>
       else el.value = val;
     }
   });
+  // Populate the inverter model dropdown now that settings (and its options
+  // list) are loaded.
+  populateInverterModels();
 }
 
 // Populate the timezone dropdown with all IANA timezones.
@@ -1044,6 +1047,21 @@ <h4 style="margin-bottom:0.5rem;">${g.title}</h4>
   const curVal = (cur !== null && typeof cur === 'object') ? cur.value : cur;
   if (curVal && list.includes(curVal)) sel.value = curVal;
 }
+
+// Populate the inverter model dropdown from the API's options list (derived
+// from the driver registry), so only real, supported models can be selected.
+function populateInverterModels() {
+  const sel = document.getElementById('inverter-model-select');
+  if (!sel) return;
+  const meta = settings.inverter_model;
+  const options = (meta && Array.isArray(meta.options)) ? meta.options : [];
+  // options is a list of [value, label] pairs from the API.
+  const list = options.map(o => (Array.isArray(o) ? o : [o.value, o.label]));
+  sel.innerHTML = list.map(([v, l]) => `<option value="${v}">${l}</option>`).join('');
+  // Preserve the currently-configured model if present.
+  const curVal = (meta !== null && typeof meta === 'object') ? meta.value : meta;
+  if (curVal && list.some(([v]) => v === curVal)) sel.value = curVal;
+}
 async function saveConfiguration() {
   const msg = document.getElementById('config-msg');
   msg.textContent = 'Saving...'; msg.style.color = 'var(--light-text-color)';

collector/settings.py

@@ -220,21 +220,46 @@ def effective_value(name: str, db_value: Optional[str]):
 
 # ── Setting metadata for the UI ──
 
-# Each setting's display info for the settings page form
-SETTING_META = {
-    "inverter_model": {
-        "label": "Model",
-        "type": "select",
-        "section": "inverter",
-        "options": [
+
+def _inverter_model_options():
+    """Return the (value, label) pairs for the inverter_model dropdown.
+
+    Derived from the driver registry so the settings page can never drift out
+    of sync with the drivers that actually exist. Imported lazily to avoid a
+    circular import (registry -> registers, not settings).
+    """
+    try:
+        from .drivers.registry import DRIVERS
+        from .drivers import ModelDriver
+        options = []
+        for name in sorted(DRIVERS):
+            try:
+                drv = DRIVERS[name]()
+                label = drv.label if isinstance(drv, ModelDriver) else name
+            except Exception:
+                label = name
+            options.append((name, label))
+        return options
+    except Exception:
+        # Fall back to a static list if the registry can't be imported.
+        return [
             ("eg4_6000xp", "EG4 6000XP"),
             ("eg4_12000xp", "EG4 12000XP"),
             ("eg4_18kpv", "EG4 18KPV"),
             ("eg4_12kpv", "EG4 12kPV"),
             ("luxpower_sna", "Luxpower SNA"),
             ("eg4_6500ex", "EG4 6500EX-48 (legacy)"),
             ("eg4_3000ehv", "EG4 3000EHV-48 (legacy)"),
-        ],
+        ]
+
+
+# Each setting's display info for the settings page form
+SETTING_META = {
+    "inverter_model": {
+        "label": "Model",
+        "type": "select",
+        "section": "inverter",
+        "options": _inverter_model_options(),
         "hint": "Inverter model (Luxpower SNA / 18KPV families only)",
     },
     "pv_max_power": {