feat(core): add bounded key creation contract

Expose create_redis_value through the Tauri bridge, add NX-based string creation in redis-core, and surface duplicate-key handling through stable operator notices.

Co-Authored-By: Paperclip <noreply@paperclip.ing>

apps/desktop/src-tauri/src/main.rs

@@ -2,8 +2,9 @@ use redis_core::{
     BackendBootstrap, BackendError, CommandExecutionResult, ConnectionTestResult,
     RedisCommandRequest, RedisConnectionRequest, RedisKeyBrowseRequest, RedisKeyBrowseResult,
     RedisKeyMetadata, RedisKeyMetadataRequest, RedisKeyTtlUpdateRequest, RedisKeyTtlUpdateResult,
-    RedisValueReadRequest, RedisValueRecord, RedisValueWriteRequest, browse_keys, execute_command,
-    inspect_key, read_value, test_connection, update_key_ttl, write_value,
+    RedisValueCreateRequest, RedisValueCreateResult, RedisValueReadRequest, RedisValueRecord,
+    RedisValueWriteRequest, browse_keys, create_value, execute_command, inspect_key, read_value,
+    test_connection, update_key_ttl, write_value,
 };
 
 #[tauri::command]
@@ -45,6 +46,13 @@ fn write_redis_value(request: RedisValueWriteRequest) -> Result<RedisValueRecord
     write_value(request)
 }
 
+#[tauri::command]
+fn create_redis_value(
+    request: RedisValueCreateRequest,
+) -> Result<RedisValueCreateResult, BackendError> {
+    create_value(request)
+}
+
 #[tauri::command]
 fn update_redis_key_ttl(
     request: RedisKeyTtlUpdateRequest,
@@ -62,6 +70,7 @@ fn main() {
             inspect_redis_key,
             read_redis_value,
             write_redis_value,
+            create_redis_value,
             update_redis_key_ttl
         ])
         .run(tauri::generate_context!())

apps/desktop/src/lib/operator-notices.test.ts

@@ -65,6 +65,28 @@ describe("operator notices", () => {
     );
   });
 
+  it("maps duplicate key creation into a stable neutral notice", () => {
+    expect(
+      toBackendErrorNotice(
+        {
+          code: "already_exists",
+          message: "Redis key creation does not overwrite an existing key.",
+          detail: "key `draft:key` already exists",
+        },
+        {
+          operation: "key_create",
+          connectionName: "redis-local-fixture",
+          databaseLabel: "db0",
+          keyName: "draft:key",
+        },
+      ),
+    ).toEqual(
+      createNeutralNotice(
+        "Redis refused to proceed while creating draft:key on redis-local-fixture / db0 because the key already exists. Choose a new key name or inspect the existing key before retrying. Backend detail: Redis key creation does not overwrite an existing key. (key `draft:key` already exists).",
+      ),
+    );
+  });
+
   it("describes command failures with command and scope context", () => {
     expect(
       toBackendErrorNotice(

apps/desktop/src/lib/operator-notices.ts

@@ -9,6 +9,7 @@ export type BackendErrorCode =
   | "invalid_connection_config"
   | "unsupported_tls_mode"
   | "unsupported_operation"
+  | "already_exists"
   | "connection_failed"
   | "authentication_failed"
   | "command_failed"
@@ -21,6 +22,12 @@ export type BackendError = {
 };
 
 export type BackendErrorContext =
+  | {
+      operation: "key_create";
+      connectionName: string;
+      databaseLabel: string;
+      keyName: string;
+    }
   | {
       operation: "connection_test";
       connectionName: string;
@@ -96,6 +103,7 @@ export function toBackendErrorNotice(
   const backendError = toBackendError(error);
   const tone =
     backendError.code === "invalid_connection_config" ||
+    backendError.code === "already_exists" ||
     backendError.code === "unsupported_operation" ||
     backendError.code === "unsupported_tls_mode"
       ? "neutral"
@@ -115,6 +123,7 @@ function normalizeBackendErrorCode(value: unknown): BackendErrorCode {
   switch (value) {
     case "invalid_connection_config":
     case "unsupported_tls_mode":
+    case "already_exists":
     case "unsupported_operation":
     case "connection_failed":
     case "authentication_failed":
@@ -134,6 +143,8 @@ function buildHeadline(error: BackendError, context: BackendErrorContext) {
       return `The request for ${target} was rejected before Redis was contacted.`;
     case "unsupported_tls_mode":
       return `The request for ${target} requires TLS handling that this foundation build does not support yet.`;
+    case "already_exists":
+      return `Redis refused to proceed while ${target} because the key already exists.`;
     case "unsupported_operation":
       return `The current desktop contract does not allow ${target} yet.`;
     case "connection_failed":
@@ -155,6 +166,8 @@ function buildHint(code: BackendErrorCode, context: BackendErrorContext) {
       return "Check host, port, database, search pattern, and key input before retrying.";
     case "unsupported_tls_mode":
       return "Keep TLS disabled in this foundation build unless product scope explicitly adds transport controls.";
+    case "already_exists":
+      return "Choose a new key name or inspect the existing key before retrying.";
     case "unsupported_operation":
       return "Stay on the visible read-only path or wait for a backend contract change before retrying.";
     case "connection_failed":
@@ -181,6 +194,8 @@ function describeContext(context: BackendErrorContext) {
   switch (context.operation) {
     case "connection_test":
       return `testing ${context.connectionName} on ${context.databaseLabel}`;
+    case "key_create":
+      return `creating ${context.keyName} on ${context.connectionName} / ${context.databaseLabel}`;
     case "key_browse":
       return `loading keys from ${context.connectionName} / ${context.databaseLabel}`;
     case "value_read":