fix(ai-chat): stop 100% CPU freeze during streaming (#1205)

CHANGELOG.md

@@ -98,6 +98,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Fixed
 
+- AI Chat: Copilot Agent mode now persists across follow-up turns. The chat-mode flag was only set on `conversationCreate`, so the first message in a conversation ran with tools but the second and later messages reverted to plain chat (the model would say "I don't have access to query execution tools"). `CopilotConversationTurnParams` now carries `chatMode`, `customChatModeId`, and `needToolCallConfirmation`, and `streamChat` sends them on every turn
+- iOS: data browser no longer flashes the "No Data" empty state mid-reload when the search field is cleared, filters change, sort changes, or page size changes. `DataBrowserViewModel.load()` now sets `isPageLoading` when rows already exist (so the in-list overlay shows during the reload), and the view renders a progress spinner instead of the empty state while a reload is in flight (reported via TestFlight, iPhone 17 Pro / iOS 26.4.2)
+- AI Chat: streaming responses no longer hang the process at 100% CPU, and Agent-mode assistant turns that emit text before a tool call now show that text above the tool card (it previously appeared below). The previous design rebuilt the assistant turn's text block on every 150 ms flush, recomputed `plainText` from blocks on every observer tick, and re-fed the result to `Markdown(text)` keyed by `\.offset`, making MarkdownUI reparse the full message every flush. The fix is structural: an assistant turn is now a single ordered list of `ChatContentBlock` reference instances (`@Observable` classes with stable UUIDs), tokens flow directly into the trailing streaming block, and tool blocks are appended after a `finishStreamingTextBlock()` call so text emitted before any tool call lands first. Per-property Observation scopes re-renders to the one streaming text view; siblings are not invalidated. Markdown rendering moved off the third-party `swift-markdown-ui` dependency to a native renderer built on Foundation's `AttributedString(markdown:)` with SwiftUI block layout (paragraphs, headers, lists, blockquotes, fenced code, GFM tables). Schema prefetch and turn resolution run on `Task.detached` so the main thread stays free between flushes. Providers and persistence now operate on a separate `ChatTurnWire` value type, so live message instances never cross actor boundaries (#1205)
 - MySQL/MariaDB: `BINARY(N)` and `VARBINARY(N)` columns are no longer classified as text. The plugin's type switch returned `"CHAR"` for type code 254 and `"VARCHAR"` for type code 253 without consulting the binary flag, so binary columns came through as `.text` instead of `.blob`. The data grid then allowed inline edit on those cells, the editor opened with an empty field (because `PluginCellValue.bytes(_).asText` returns `nil`), and focus-out marked the cell as modified-to-empty. A single accidental click was enough to schedule destruction of the original bytes on Save. Case 253 now returns `"VARBINARY"` and case 254 returns `"BINARY"` when the binary flag is set, so these cells route through the blob editor (chevron-triggered) instead of inline text edit
 - Data grid: dropdown / boolean / date / JSON / blob cells now show or hide their chevron accessory when the cell's editability changes (refresh, safe-mode toggle, view-to-table switch). The performance pass in #1212 made `configure` skip `needsDisplay = true` when nothing visible changed, but the editability flag was updated unconditionally without flagging a redraw, so chevrons could stick in their stale state (visible in `audit_log.payload` JSON cells after save / refresh / reopen)
 - MySQL/MariaDB: JSON column detection no longer flickers across refreshes. The plugin reads `mariadb_field_attr(MARIADB_FIELD_ATTR_FORMAT_NAME)` to recognize JSON-stored-as-LONGTEXT. The returned `MARIADB_CONST_STRING` is a length-prefixed buffer (not null-terminated), but we were reading it with `String(cString:)`, which scans bytes until the next `\0` and so reads past the buffer into adjacent memory. When that memory happened to contain a null byte the comparison passed and we tagged the column `JSON`; when it contained garbage the comparison failed and we fell through to `LONGTEXT`. Read exactly `attr.length` bytes via `String(data: Data(bytes:count:), encoding: .utf8)`

TablePro.xcodeproj/project.pbxproj

@@ -54,7 +54,6 @@
 		5ACE00012F4F000000000005 /* CodeEditLanguages in Frameworks */ = {isa = PBXBuildFile; productRef = 5ACE00012F4F000000000003 /* CodeEditLanguages */; };
 		5ACE00012F4F000000000006 /* CodeEditTextView in Frameworks */ = {isa = PBXBuildFile; productRef = 5ACE00012F4F000000000007 /* CodeEditTextView */; };
 		5ACE00012F4F00000000000A /* Sparkle in Frameworks */ = {isa = PBXBuildFile; productRef = 5ACE00012F4F000000000009 /* Sparkle */; };
-		5ACE00012F4F00000000000D /* MarkdownUI in Frameworks */ = {isa = PBXBuildFile; productRef = 5ACE00012F4F00000000000C /* MarkdownUI */; };
 		5ADDB00100000000000000A1 /* DynamoDBConnection.swift in Sources */ = {isa = PBXBuildFile; fileRef = 5ADDB00200000000000000A1 /* DynamoDBConnection.swift */; };
 		5ADDB00100000000000000A2 /* DynamoDBItemFlattener.swift in Sources */ = {isa = PBXBuildFile; fileRef = 5ADDB00200000000000000A2 /* DynamoDBItemFlattener.swift */; };
 		5ADDB00100000000000000A3 /* DynamoDBPartiQLParser.swift in Sources */ = {isa = PBXBuildFile; fileRef = 5ADDB00200000000000000A3 /* DynamoDBPartiQLParser.swift */; };
@@ -674,7 +673,6 @@
 				5A32BBFB2F9D5EAB00BAEB5F /* X509 in Frameworks */,
 				5ACE00012F4F000000000006 /* CodeEditTextView in Frameworks */,
 				5ACE00012F4F00000000000A /* Sparkle in Frameworks */,
-				5ACE00012F4F00000000000D /* MarkdownUI in Frameworks */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};
@@ -1049,7 +1047,6 @@
 				5ACE00012F4F000000000003 /* CodeEditLanguages */,
 				5ACE00012F4F000000000007 /* CodeEditTextView */,
 				5ACE00012F4F000000000009 /* Sparkle */,
-				5ACE00012F4F00000000000C /* MarkdownUI */,
 				5A3A69B72F976F38000AC5B2 /* GhosttyTerminal */,
 				5A3A69B92F976F38000AC5B2 /* GhosttyTheme */,
 				5ACE00012F4F000000000010 /* TableProAnalytics */,
@@ -1640,7 +1637,6 @@
 			packageReferences = (
 				5A0000012F4F000000000101 /* XCLocalSwiftPackageReference "LocalPackages/CodeEditSourceEditor" */,
 				5ACE00012F4F000000000008 /* XCRemoteSwiftPackageReference "Sparkle" */,
-				5ACE00012F4F00000000000B /* XCRemoteSwiftPackageReference "swift-markdown-ui" */,
 				5A0000012F4F000000000100 /* XCLocalSwiftPackageReference "LocalPackages/CodeEditLanguages" */,
 				5ACE00012F4F00000000000E /* XCRemoteSwiftPackageReference "oracle-nio" */,
 				5A3A69B62F976F38000AC5B2 /* XCRemoteSwiftPackageReference "libghostty-spm" */,
@@ -4054,14 +4050,6 @@
 				minimumVersion = 2.0.0;
 			};
 		};
-		5ACE00012F4F00000000000B /* XCRemoteSwiftPackageReference "swift-markdown-ui" */ = {
-			isa = XCRemoteSwiftPackageReference;
-			repositoryURL = "https://github.com/gonzalezreal/swift-markdown-ui";
-			requirement = {
-				kind = upToNextMajorVersion;
-				minimumVersion = 2.0.0;
-			};
-		};
 		5ACE00012F4F00000000000E /* XCRemoteSwiftPackageReference "oracle-nio" */ = {
 			isa = XCRemoteSwiftPackageReference;
 			repositoryURL = "https://github.com/TableProApp/oracle-nio";
@@ -4105,11 +4093,6 @@
 			package = 5ACE00012F4F000000000008 /* XCRemoteSwiftPackageReference "Sparkle" */;
 			productName = Sparkle;
 		};
-		5ACE00012F4F00000000000C /* MarkdownUI */ = {
-			isa = XCSwiftPackageProductDependency;
-			package = 5ACE00012F4F00000000000B /* XCRemoteSwiftPackageReference "swift-markdown-ui" */;
-			productName = MarkdownUI;
-		};
 		5ACE00012F4F00000000000F /* OracleNIO */ = {
 			isa = XCSwiftPackageProductDependency;
 			package = 5ACE00012F4F00000000000E /* XCRemoteSwiftPackageReference "oracle-nio" */;

TablePro/Core/AI/AnthropicProvider.swift

@@ -24,7 +24,7 @@ final class AnthropicProvider: ChatTransport {
     }
 
     func streamChat(
-        turns: [ChatTurn],
+        turns: [ChatTurnWire],
         options: ChatTransportOptions
     ) -> AsyncThrowingStream<ChatStreamEvent, Error> {
         AsyncThrowingStream { continuation in
@@ -111,7 +111,7 @@ final class AnthropicProvider: ChatTransport {
 
     func testConnection() async throws -> Bool {
         let testModel = model.isEmpty ? (Self.knownModels.first ?? "") : model
-        let testTurn = ChatTurn(role: .user, blocks: [.text("Hi")])
+        let testTurn = ChatTurnWire(role: .user, blocks: [.text("Hi")])
         let testOptions = ChatTransportOptions(model: testModel, maxOutputTokens: 1)
         let request = try buildMessagesRequest(turns: [testTurn], options: testOptions, stream: false)
 
@@ -136,7 +136,7 @@ final class AnthropicProvider: ChatTransport {
     }
 
     private func buildMessagesRequest(
-        turns: [ChatTurn],
+        turns: [ChatTurnWire],
         options: ChatTransportOptions,
         stream: Bool = true
     ) throws -> URLRequest {
@@ -256,10 +256,10 @@ final class AnthropicProvider: ChatTransport {
         ]
     }
 
-    static func encodeTurn(_ turn: ChatTurn) throws -> [String: Any]? {
+    static func encodeTurn(_ turn: ChatTurnWire) throws -> [String: Any]? {
         let blocks = turn.blocks
         let needsTypedBlocks = blocks.contains { block in
-            switch block {
+            switch block.kind {
             case .toolUse, .toolResult:
                 return true
             case .text, .attachment:
@@ -278,8 +278,8 @@ final class AnthropicProvider: ChatTransport {
         return ["role": turn.role.rawValue, "content": text]
     }
 
-    static func encodeBlock(_ block: ChatContentBlock) throws -> [String: Any]? {
-        switch block {
+    static func encodeBlock(_ block: ChatContentBlockWire) throws -> [String: Any]? {
+        switch block.kind {
         case .text(let text):
             guard !text.isEmpty else { return nil }
             return ["type": "text", "text": text]

TablePro/Core/AI/Chat/ChatTransport.swift

@@ -7,7 +7,7 @@ import Foundation
 
 protocol ChatTransport: AnyObject, Sendable {
     func streamChat(
-        turns: [ChatTurn],
+        turns: [ChatTurnWire],
         options: ChatTransportOptions
     ) -> AsyncThrowingStream<ChatStreamEvent, Error>