fix(auth): SDK'yı kaldırıp ince REST katmanına geç (lib/appwrite-rest.ts)

Sorun:
- node-appwrite v20-25 hepsi Node 26'da bozuk (node-fetch-native-with-agent polyfill)
- appwrite browser SDK Server Action context'inde 'unexpected response' veriyor
  (büyük olasılıkla browser-only global'ları kontrol ederken)

Çözüm:
- Tüm Appwrite SDK'larını sil (appwrite + node-appwrite)
- lib/appwrite-rest.ts: native fetch üzerinde ~250 satırlık ince REST wrapper
  - account: createEmailPasswordSession, get, deleteSession
  - tablesDB: listRows, getRow, createRow, updateRow, deleteRow
  - storage: listFiles, createFile, deleteFile, fileViewUrl
  - Q helpers: equal, orderAsc/Desc, limit, offset
  - AppwriteError class
- Session secret cookie tabanlı auth korundu (isletmem-kovakcrm'deki desen)
- Tüm CRUD action ve query'ler REST katmanına bağlandı

End-to-end test edildi:
✓ Login (proper 401 hata mesajları, başarılı durumda redirect)
✓ Public read (services, blog, testimonials)
✓ Anonim create (contact form)
✓ Build (24 route)
✓ Sıfır SDK bağımlılığı — Node 26 sorunu yok

lib/types.ts

@@ -1,6 +1,8 @@
-import type { Models } from "appwrite";
+import type { AwRow } from "@/lib/appwrite-rest";
 
-export interface ServiceRow extends Models.Row {
+export type Row = AwRow;
+
+export interface ServiceRow extends AwRow {
   slug: string;
   title: string;
   description: string;
@@ -9,7 +11,7 @@ export interface ServiceRow extends Models.Row {
   featured?: boolean | null;
 }
 
-export interface ProjectRow extends Models.Row {
+export interface ProjectRow extends AwRow {
   slug: string;
   title: string;
   description: string;
@@ -21,7 +23,7 @@ export interface ProjectRow extends Models.Row {
   featured?: boolean | null;
 }
 
-export interface BlogPostRow extends Models.Row {
+export interface BlogPostRow extends AwRow {
   slug: string;
   title: string;
   excerpt?: string | null;
@@ -37,7 +39,7 @@ export interface BlogPostRow extends Models.Row {
   seo_image?: string | null;
 }
 
-export interface TestimonialRow extends Models.Row {
+export interface TestimonialRow extends AwRow {
   name: string;
   role?: string | null;
   company?: string | null;
@@ -48,7 +50,7 @@ export interface TestimonialRow extends Models.Row {
   featured?: boolean | null;
 }
 
-export interface SeoPageRow extends Models.Row {
+export interface SeoPageRow extends AwRow {
   path: string;
   title?: string | null;
   description?: string | null;
@@ -57,7 +59,7 @@ export interface SeoPageRow extends Models.Row {
   noindex?: boolean | null;
 }
 
-export interface SeoSettingsRow extends Models.Row {
+export interface SeoSettingsRow extends AwRow {
   site_name?: string | null;
   site_description?: string | null;
   default_og_image?: string | null;
@@ -69,7 +71,7 @@ export interface SeoSettingsRow extends Models.Row {
   gtm_id?: string | null;
 }
 
-export interface ContactMessageRow extends Models.Row {
+export interface ContactMessageRow extends AwRow {
   name: string;
   email: string;
   phone?: string | null;