Add VO management, tariff-option assignment, and 2-step schaltung wizard

VOs (Vertriebspartner-Nummern)
- New vos table (one row per VO, scoped to a provider). Migrations
  add tarife.vo_id and schaltungen.vo_id columns (nullable so legacy
  rows survive).
- New /api/vos CRUD (list, create, update, delete with use-checks).
- Admin: new "VOs (Vertriebspartner)" sub-tab. List/create with
  provider dropdown; edit via prompt; delete refuses while used.
- /api/tarife?vo_id=X filter for fetching tariffs of a specific VO.

Tariff editor
- Add-tariff form requires a VO; new dependent VO dropdown that
  populates after the provider is chosen.
- Edit-tariff modal now shows the VO dropdown and a checkbox grid of
  all anbieter-wide tarifoptionen. Saving the dialog applies the
  selection via the existing tarifoptionen_tarife table.
- New GET /api/tarife/:id/tarifoptionen-multi returns the option set
  scoped to the tariff's provider, each annotated with whether it is
  currently assigned to this tariff.
- POST/PUT /api/tarife accept vo_id (required for create, validated
  against the provider) and an optional tarifoption_ids array.

Schaltung wizard
- The Schaltung-erfassen tab is now a 2-step wizard:
  step 1 picks a provider from a button row (mirrors the screenshot
  the user shared); step 2 shows a 2-column form mirroring the
  Aktivierungs-/Vertragsdaten layout.
- Step 2 cascades: VO -> tariffs filtered by VO -> tarifoptionen
  filtered by tariff. Erfasser is autofilled from the logged-in user
  (read-only).
- Removed customer fields that the user does not need (Kundennummer,
  Kennwort/Service-PIN never existed; Rufnummer is now optional both
  in the form and in the API validation).
- After saving, the wizard resets to step 1 ready for the next entry.

Schema
- tarife: vo_id added.
- schaltungen: vo_id added; rufnummer is nullable in new DBs.
  Existing DBs may still have NOT NULL on rufnummer; the schaltungen
  route now sends an empty string instead of NULL to remain
  compatible.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

routes/tarife.js

@@ -9,23 +9,38 @@ function validateAmount(amount) {
 }
 
 router.get('/', asyncHandler(async (req, res) => {
+    const { vo_id } = req.query;
+    const params = [];
+    let where = '';
+    if (vo_id) {
+        where = 'WHERE t.vo_id = ?';
+        params.push(vo_id);
+    }
     const rows = await db.all(
-        `SELECT t.*, a.name AS anbieter_name
+        `SELECT t.*, a.name AS anbieter_name, v.nummer AS vo_nummer, v.bezeichnung AS vo_bezeichnung
          FROM tarife t
          JOIN anbieter a ON t.anbieter_id = a.id
-         ORDER BY a.name, t.name`
+         LEFT JOIN vos v ON t.vo_id = v.id
+         ${where}
+         ORDER BY a.name, t.name`,
+        params
     );
     res.json(rows);
 }));
 
 router.get('/:anbieter_id', asyncHandler(async (req, res) => {
     const { anbieter_id } = req.params;
-    const rows = await db.all('SELECT * FROM tarife WHERE anbieter_id = ? ORDER BY name', [anbieter_id]);
+    const rows = await db.all(
+        `SELECT t.*, v.nummer AS vo_nummer, v.bezeichnung AS vo_bezeichnung
+         FROM tarife t LEFT JOIN vos v ON t.vo_id = v.id
+         WHERE t.anbieter_id = ? ORDER BY t.name`,
+        [anbieter_id]
+    );
     res.json(rows);
 }));
 
 router.post('/', asyncHandler(async (req, res) => {
-    const { name, anbieter_id, provision_euro, beschreibung } = req.body || {};
+    const { name, anbieter_id, vo_id, provision_euro, beschreibung, tarifoption_ids } = req.body || {};
 
     if (!name || !name.trim()) {
         return res.status(400).json({ error: 'Tarifname ist erforderlich' });
@@ -33,19 +48,40 @@ router.post('/', asyncHandler(async (req, res) => {
     if (!anbieter_id) {
         return res.status(400).json({ error: 'Anbieter ist erforderlich' });
     }
+    if (!vo_id) {
+        return res.status(400).json({ error: 'VO ist erforderlich' });
+    }
+    // Make sure the VO actually belongs to the same provider.
+    const vo = await db.get('SELECT anbieter_id FROM vos WHERE id = ?', [vo_id]);
+    if (!vo) return res.status(400).json({ error: 'VO nicht gefunden' });
+    if (vo.anbieter_id !== Number(anbieter_id)) {
+        return res.status(400).json({ error: 'VO gehört nicht zum gewählten Anbieter' });
+    }
     if (!validateAmount(provision_euro)) {
         return res.status(400).json({ error: 'Provision muss eine positive Zahl sein' });
     }
 
     try {
-        const result = await db.run(
-            `INSERT INTO tarife (name, anbieter_id, provision_euro, beschreibung) VALUES (?, ?, ?, ?)`,
-            [name.trim(), anbieter_id, provision_euro || 0, beschreibung || null]
-        );
+        const tarifId = await db.transaction(async () => {
+            const result = await db.run(
+                `INSERT INTO tarife (name, anbieter_id, vo_id, provision_euro, beschreibung) VALUES (?, ?, ?, ?, ?)`,
+                [name.trim(), anbieter_id, vo_id, provision_euro || 0, beschreibung || null]
+            );
+            if (Array.isArray(tarifoption_ids)) {
+                for (const optId of tarifoption_ids) {
+                    await db.run(
+                        'INSERT OR IGNORE INTO tarifoptionen_tarife (tarifoption_id, tarif_id) VALUES (?, ?)',
+                        [optId, result.lastID]
+                    );
+                }
+            }
+            return result.lastID;
+        });
         res.json({
-            id: result.lastID,
+            id: tarifId,
             name: name.trim(),
             anbieter_id,
+            vo_id,
             provision_euro: provision_euro || 0,
             beschreibung: beschreibung || null,
         });
@@ -59,19 +95,65 @@ router.post('/', asyncHandler(async (req, res) => {
 
 router.put('/:id', asyncHandler(async (req, res) => {
     const { id } = req.params;
-    const { name, provision_euro, beschreibung } = req.body || {};
+    const { name, vo_id, provision_euro, beschreibung, tarifoption_ids } = req.body || {};
     if (!name) return res.status(400).json({ error: 'Tarif-Name ist erforderlich' });
     if (!validateAmount(provision_euro)) {
         return res.status(400).json({ error: 'Provision muss eine positive Zahl sein' });
     }
-    const result = await db.run(
-        `UPDATE tarife SET name = ?, provision_euro = ?, beschreibung = ? WHERE id = ?`,
-        [name, provision_euro || 0, beschreibung || null, id]
-    );
-    if (result.changes === 0) return res.status(404).json({ error: 'Tarif nicht gefunden' });
+    const current = await db.get('SELECT anbieter_id FROM tarife WHERE id = ?', [id]);
+    if (!current) return res.status(404).json({ error: 'Tarif nicht gefunden' });
+
+    if (vo_id) {
+        const vo = await db.get('SELECT anbieter_id FROM vos WHERE id = ?', [vo_id]);
+        if (!vo) return res.status(400).json({ error: 'VO nicht gefunden' });
+        if (vo.anbieter_id !== current.anbieter_id) {
+            return res.status(400).json({ error: 'VO gehört nicht zum Anbieter des Tarifs' });
+        }
+    }
+
+    await db.transaction(async () => {
+        await db.run(
+            `UPDATE tarife SET name = ?, vo_id = ?, provision_euro = ?, beschreibung = ? WHERE id = ?`,
+            [name, vo_id || null, provision_euro || 0, beschreibung || null, id]
+        );
+        if (Array.isArray(tarifoption_ids)) {
+            await db.run('DELETE FROM tarifoptionen_tarife WHERE tarif_id = ?', [id]);
+            for (const optId of tarifoption_ids) {
+                await db.run(
+                    'INSERT OR IGNORE INTO tarifoptionen_tarife (tarifoption_id, tarif_id) VALUES (?, ?)',
+                    [optId, id]
+                );
+            }
+        }
+    });
     res.json({ message: 'Tarif erfolgreich aktualisiert' });
 }));
 
+// All tarifoptionen of this tariff's provider, each annotated with whether it
+// is currently assigned to this tariff. Frontend uses this to render the
+// checkbox grid in the tariff editor.
+router.get('/:id/tarifoptionen-multi', asyncHandler(async (req, res) => {
+    const { id } = req.params;
+    const tarif = await db.get('SELECT anbieter_id FROM tarife WHERE id = ?', [id]);
+    if (!tarif) return res.status(404).json({ error: 'Tarif nicht gefunden' });
+    const rows = await db.all(
+        `SELECT tn.id, tn.name, tn.code, tn.provision_euro, tn.beschreibung,
+                CASE WHEN tt.tarifoption_id IS NULL THEN 0 ELSE 1 END AS assigned
+         FROM tarifoptionen_new tn
+         LEFT JOIN tarifoptionen_tarife tt
+           ON tt.tarifoption_id = tn.id AND tt.tarif_id = ?
+         WHERE tn.aktiv = 1
+           AND EXISTS (
+             SELECT 1 FROM tarifoptionen_tarife tt2
+             JOIN tarife t2 ON tt2.tarif_id = t2.id
+             WHERE tt2.tarifoption_id = tn.id AND t2.anbieter_id = ?
+           )
+         ORDER BY tn.name`,
+        [id, tarif.anbieter_id]
+    );
+    res.json(rows);
+}));
+
 router.delete('/:id', asyncHandler(async (req, res) => {
     const { id } = req.params;
     const used = await db.get(