fix: remove manual project creation, smart sequence release, received-invoices schema fix

- Remove ProjectCreate page, POST /projects endpoint, and next-number endpoint
- Projects can only be created through orders (shared numbering sequence)
- Remove dead CreateProjectSchema and createProject service function
- Delete 'order' row from number_sequences (unused; code uses 'shared')
- Smart sequence release: decrement last_number only when deleting the highest number
- Fix received-invoices stats referencing non-existent is_deleted and amount_czk columns
- Update deploy instructions in CLAUDE.md (npm install, prisma migrate deploy)

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

src/services/numbering.service.ts

@@ -110,13 +110,51 @@ async function previewNextSequence(
 
 /**
  * Release a sequence number back to the pool.
- * NOTE: Blindly decrementing can cause duplicate numbers if numbers were
- * allocated after this one. Sequence numbers are consumed but not returned
- * to the pool — this is intentionally a no-op.
+ * Only decrements if the deleted entity held the current highest number,
+ * preventing gaps while avoiding duplicate re-allocation.
  */
-async function releaseSequence(_type: string, _year: number) {
-  // No-op: decrementing can cause duplicate sequence numbers.
-  // Sequence numbers are consumed but never returned to the pool.
+async function releaseSequence(
+  type: string,
+  year: number,
+  deletedNumber?: string,
+) {
+  if (!deletedNumber) return;
+
+  const existing = await prisma.$queryRaw<Array<{ last_number: number }>>`
+    SELECT last_number FROM number_sequences
+    WHERE \`type\` = ${type} AND \`year\` = ${year}
+  `;
+  if (existing.length === 0) return;
+
+  const settings = await getSettings();
+  const pattern =
+    type === "shared"
+      ? settings?.order_number_pattern || DEFAULT_ORDER_PATTERN
+      : type === "invoice"
+        ? settings?.invoice_number_pattern || DEFAULT_INVOICE_PATTERN
+        : settings?.offer_number_pattern || DEFAULT_OFFER_PATTERN;
+  const code =
+    type === "shared"
+      ? settings?.order_type_code || "71"
+      : type === "invoice"
+        ? settings?.invoice_type_code || "81"
+        : "";
+  const prefix = type === "offer" ? settings?.quotation_prefix || "NA" : "";
+
+  const highestNumber = applyPattern(pattern, {
+    year,
+    prefix,
+    code,
+    seq: existing[0].last_number,
+  });
+
+  if (deletedNumber === highestNumber && existing[0].last_number > 0) {
+    await prisma.$executeRaw`
+      UPDATE number_sequences
+      SET \`last_number\` = ${existing[0].last_number - 1}
+      WHERE \`type\` = ${type} AND \`year\` = ${year}
+    `;
+  }
 }
 
 /** Verify a shared number is not already used by an order or project. */
@@ -265,19 +303,40 @@ export async function previewInvoiceNumber(
   return { number, next_number: number };
 }
 
-/** Release an offer number back to the pool (decrement sequence). */
-export async function releaseOfferNumber(year?: number) {
-  await releaseSequence("offer", year || new Date().getFullYear());
+/** Release an offer number back to the pool (decrement if highest). */
+export async function releaseOfferNumber(
+  year?: number,
+  deletedNumber?: string,
+) {
+  await releaseSequence(
+    "offer",
+    year || new Date().getFullYear(),
+    deletedNumber,
+  );
 }
 
-/** Release a shared number back to the pool (decrement sequence). */
-export async function releaseSharedNumber(year?: number) {
-  await releaseSequence("shared", year || new Date().getFullYear());
+/** Release a shared number back to the pool (decrement if highest). */
+export async function releaseSharedNumber(
+  year?: number,
+  deletedNumber?: string,
+) {
+  await releaseSequence(
+    "shared",
+    year || new Date().getFullYear(),
+    deletedNumber,
+  );
 }
 
-/** Release an invoice number back to the pool (decrement sequence). */
-export async function releaseInvoiceNumber(year?: number) {
-  await releaseSequence("invoice", year || new Date().getFullYear());
+/** Release an invoice number back to the pool (decrement if highest). */
+export async function releaseInvoiceNumber(
+  year?: number,
+  deletedNumber?: string,
+) {
+  await releaseSequence(
+    "invoice",
+    year || new Date().getFullYear(),
+    deletedNumber,
+  );
 }
 
 /** Preview what a pattern would produce (for settings UI) */