feat: integrate shared AI provider with safe execution evidence

backend/src/main/java/com/devflow/copilot/common/GlobalExceptionHandler.java

@@ -41,8 +41,21 @@ public ResponseEntity<ApiResponse<Void>> handleIllegalArgument(IllegalArgumentEx
 
     @ExceptionHandler(Exception.class)
     public ResponseEntity<ApiResponse<Void>> handleException(Exception ex) {
-        log.error("Unhandled request error", ex);
+        if (containsProviderException(ex)) {
+            log.error("Unhandled provider request error type: {}", ex.getClass().getSimpleName());
+        } else {
+            log.error("Unhandled request error", ex);
+        }
         return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR)
                 .body(ApiResponse.fail(5000, "服务处理失败，请查看后端日志"));
     }
+
+    private boolean containsProviderException(Throwable exception) {
+        for (Throwable current = exception; current != null; current = current.getCause()) {
+            if (current instanceof LlmProviderException) {
+                return true;
+            }
+        }
+        return false;
+    }
 }

backend/src/main/java/com/devflow/copilot/common/LlmProviderException.java

@@ -1,15 +1,57 @@
 package com.devflow.copilot.common;
 
+import com.fasterxml.jackson.annotation.JsonIgnore;
+import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
 import org.springframework.http.HttpStatus;
 
+@JsonIgnoreProperties({"cause", "stackTrace", "suppressed", "localizedMessage"})
 public class LlmProviderException extends BusinessException {
 
-    public LlmProviderException(String message) {
-        super(5001, HttpStatus.BAD_GATEWAY, message);
+    private final ProviderErrorType errorType;
+    private final ProviderFailureMetadata failureMetadata;
+
+    public LlmProviderException(ProviderErrorType errorType) {
+        this(errorType, ProviderFailureMetadata.unknown(), null);
+    }
+
+    public LlmProviderException(ProviderErrorType errorType, Throwable cause) {
+        this(errorType, ProviderFailureMetadata.unknown(), cause);
+    }
+
+    public LlmProviderException(ProviderErrorType errorType, ProviderFailureMetadata failureMetadata) {
+        this(errorType, failureMetadata, null);
+    }
+
+    public LlmProviderException(ProviderErrorType errorType, ProviderFailureMetadata failureMetadata, Throwable cause) {
+        super(5001, HttpStatus.BAD_GATEWAY, errorType.safeMessage());
+        this.errorType = errorType;
+        this.failureMetadata = failureMetadata == null ? ProviderFailureMetadata.unknown() : failureMetadata;
+        if (cause != null) {
+            initCause(cause);
+        }
+    }
+
+    public ProviderErrorType getErrorType() {
+        return errorType;
+    }
+
+    public ProviderFailureMetadata getFailureMetadata() {
+        return failureMetadata;
+    }
+
+    @Override
+    public String getMessage() {
+        return errorType.safeMessage();
+    }
+
+    @Override
+    @JsonIgnore
+    public synchronized Throwable getCause() {
+        return super.getCause();
     }
 
-    public LlmProviderException(String message, Throwable cause) {
-        super(5001, HttpStatus.BAD_GATEWAY, message);
-        initCause(cause);
+    @Override
+    public String toString() {
+        return getClass().getName() + ": " + getMessage();
     }
 }

backend/src/main/java/com/devflow/copilot/common/ProviderContentTypeCategory.java

@@ -0,0 +1,9 @@
+package com.devflow.copilot.common;
+
+public enum ProviderContentTypeCategory {
+    JSON,
+    HTML,
+    TEXT,
+    OTHER,
+    UNKNOWN
+}

backend/src/main/java/com/devflow/copilot/common/ProviderDurationBucket.java

@@ -0,0 +1,11 @@
+package com.devflow.copilot.common;
+
+public enum ProviderDurationBucket {
+    UNDER_1_SECOND,
+    ONE_TO_FIVE_SECONDS,
+    FIVE_TO_FIFTEEN_SECONDS,
+    FIFTEEN_TO_SIXTY_SECONDS,
+    OVER_SIXTY_SECONDS,
+    TIMEOUT,
+    UNKNOWN
+}

backend/src/main/java/com/devflow/copilot/common/ProviderErrorType.java

@@ -0,0 +1,24 @@
+package com.devflow.copilot.common;
+
+public enum ProviderErrorType {
+    PROTOCOL_UNSUPPORTED("Provider protocol is unsupported."),
+    API_KEY_MISSING("Provider credential is not configured."),
+    TIMEOUT("Provider request timed out."),
+    AUTHENTICATION_FAILED("Provider authentication failed."),
+    RATE_LIMITED("Provider rate limit reached."),
+    UPSTREAM_SERVER_ERROR("Provider upstream service failed."),
+    INVALID_RESPONSE("Provider returned an invalid response."),
+    EMPTY_CONTENT("Provider returned empty content."),
+    CONNECTION_FAILED("Provider connection failed."),
+    UNKNOWN_PROVIDER_ERROR("Provider request failed.");
+
+    private final String safeSummary;
+
+    ProviderErrorType(String safeSummary) {
+        this.safeSummary = safeSummary;
+    }
+
+    public String safeMessage() {
+        return name() + ": " + safeSummary;
+    }
+}

backend/src/main/java/com/devflow/copilot/common/ProviderFailureMetadata.java

@@ -0,0 +1,50 @@
+package com.devflow.copilot.common;
+
+import java.util.UUID;
+
+/**
+ * Deliberately content-free data captured for an external provider failure.
+ * It must never contain response bodies, URLs, credentials, or header values.
+ */
+public record ProviderFailureMetadata(
+        ProviderFailureStage failureStage,
+        Integer httpStatusCode,
+        ProviderHttpStatusFamily httpStatusFamily,
+        Boolean responseBodyPresent,
+        ProviderResponseSizeBucket responseBodySizeBucket,
+        Boolean contentTypePresent,
+        ProviderContentTypeCategory contentTypeCategory,
+        Boolean retryAfterHeaderPresent,
+        Boolean upstreamRequestIdHeaderPresent,
+        String clientRequestId,
+        ProviderDurationBucket durationBucket
+) {
+
+    public ProviderFailureMetadata {
+        failureStage = failureStage == null ? ProviderFailureStage.UNKNOWN : failureStage;
+        httpStatusFamily = httpStatusFamily == null ? ProviderHttpStatusFamily.UNKNOWN : httpStatusFamily;
+        responseBodySizeBucket = responseBodySizeBucket == null ? ProviderResponseSizeBucket.UNKNOWN : responseBodySizeBucket;
+        contentTypeCategory = contentTypeCategory == null ? ProviderContentTypeCategory.UNKNOWN : contentTypeCategory;
+        durationBucket = durationBucket == null ? ProviderDurationBucket.UNKNOWN : durationBucket;
+    }
+
+    public static ProviderFailureMetadata unknown() {
+        return new ProviderFailureMetadata(
+                ProviderFailureStage.UNKNOWN, null, ProviderHttpStatusFamily.UNKNOWN,
+                null, ProviderResponseSizeBucket.UNKNOWN, null, ProviderContentTypeCategory.UNKNOWN,
+                null, null, null, ProviderDurationBucket.UNKNOWN
+        );
+    }
+
+    public static ProviderFailureMetadata atStage(ProviderFailureStage stage) {
+        return new ProviderFailureMetadata(
+                stage, null, ProviderHttpStatusFamily.UNKNOWN,
+                null, ProviderResponseSizeBucket.UNKNOWN, null, ProviderContentTypeCategory.UNKNOWN,
+                null, null, null, ProviderDurationBucket.UNKNOWN
+        );
+    }
+
+    public static String newClientRequestId() {
+        return UUID.randomUUID().toString();
+    }
+}

backend/src/main/java/com/devflow/copilot/common/ProviderFailureStage.java

@@ -0,0 +1,11 @@
+package com.devflow.copilot.common;
+
+public enum ProviderFailureStage {
+    CONFIG_VALIDATION,
+    REQUEST_BUILD,
+    CONNECTION,
+    HTTP_STATUS_RECEIVED,
+    RESPONSE_DESERIALIZATION,
+    CONTENT_EXTRACTION,
+    UNKNOWN
+}

backend/src/main/java/com/devflow/copilot/common/ProviderHttpStatusFamily.java

@@ -0,0 +1,20 @@
+package com.devflow.copilot.common;
+
+import com.fasterxml.jackson.annotation.JsonValue;
+
+public enum ProviderHttpStatusFamily {
+    FOUR_XX("4XX"),
+    FIVE_XX("5XX"),
+    UNKNOWN("UNKNOWN");
+
+    private final String value;
+
+    ProviderHttpStatusFamily(String value) {
+        this.value = value;
+    }
+
+    @JsonValue
+    public String value() {
+        return value;
+    }
+}

backend/src/main/java/com/devflow/copilot/common/ProviderResponseSizeBucket.java

@@ -0,0 +1,9 @@
+package com.devflow.copilot.common;
+
+public enum ProviderResponseSizeBucket {
+    ZERO,
+    ONE_TO_1KB,
+    ONE_TO_16KB,
+    OVER_16KB,
+    UNKNOWN
+}

backend/src/main/java/com/devflow/copilot/config/AiProviderProperties.java

@@ -6,9 +6,10 @@
 public class AiProviderProperties {
 
     private String provider = "local-rule";
-    private String baseUrl = "https://api.openai.com/v1";
+    private String baseUrl = "";
     private String apiKey = "";
     private String model = "gpt-4.1-mini";
+    private String protocol = "chat-completions-compatible";
     private int timeoutSeconds = 60;
     private int maxTokens = 2048;
     private boolean fallbackToLocal = true;
@@ -21,6 +22,8 @@ public class AiProviderProperties {
     public void setApiKey(String apiKey) { this.apiKey = apiKey; }
     public String getModel() { return model; }
     public void setModel(String model) { this.model = model; }
+    public String getProtocol() { return protocol; }
+    public void setProtocol(String protocol) { this.protocol = protocol; }
     public int getTimeoutSeconds() { return timeoutSeconds; }
     public void setTimeoutSeconds(int timeoutSeconds) { this.timeoutSeconds = timeoutSeconds; }
     public int getMaxTokens() { return maxTokens; }

backend/src/main/java/com/devflow/copilot/dto/AiGenerateResponse.java

@@ -15,6 +15,12 @@ public class AiGenerateResponse {
     private String status;
     private String providerName;
     private String modelName;
+    private String requestedProvider;
+    private String requestedModel;
+    private String actualProvider;
+    private String actualModel;
+    private Boolean fallbackUsed;
+    private String fallbackReason;
     private Long costTimeMs;
     private Integer promptTokens;
     private Integer completionTokens;

backend/src/main/java/com/devflow/copilot/entity/GenerationRecord.java

@@ -22,8 +22,12 @@ public class GenerationRecord {
     private String outputContent;
     private GenerationStatus status;
     private Boolean confirmed;
+    private String requestedProvider;
+    private String requestedModel;
     private String providerName;
     private String modelName;
+    private Boolean fallbackUsed;
+    private String fallbackReason;
     private Long promptTemplateId;
     private String promptTemplateName;
     private Integer promptTemplateVersion;
@@ -34,6 +38,17 @@ public class GenerationRecord {
     private Long costTimeMs;
     private Boolean success;
     private String errorMessage;
+    private String providerErrorType;
+    private String providerFailureStage;
+    private Integer providerHttpStatus;
+    private String providerHttpStatusFamily;
+    private String providerDurationBucket;
+    private Boolean providerResponseBodyPresent;
+    private String providerResponseSizeBucket;
+    private String providerContentTypeCategory;
+    private Boolean providerRetryAfterPresent;
+    private Boolean providerRequestIdPresent;
+    private String providerClientRequestId;
     @Version
     private Integer version;
     private LocalDateTime createdAt;

backend/src/main/java/com/devflow/copilot/service/AgentWorkflowService.java

@@ -21,6 +21,8 @@ ToolCallRecord addToolCall(Long runId, Long stepId, String toolName, String inpu
 
     void createPendingReview(Long runId, Long generationRecordId);
 
+    void updateExecutionMetadata(Long runId, String providerName, String modelName, Long latencyMs);
+
     void syncGenerationTransition(Long generationRecordId, GenerationStatus target);
 
     List<AgentRun> list(Long projectId, Long generationRecordId);

backend/src/main/java/com/devflow/copilot/service/impl/AgentWorkflowServiceImpl.java

@@ -110,6 +110,19 @@ public void createPendingReview(Long runId, Long generationRecordId) {
         humanReviewMapper.insert(review);
     }
 
+    @Override
+    public void updateExecutionMetadata(Long runId, String providerName, String modelName, Long latencyMs) {
+        AgentRun run = runMapper.selectById(runId);
+        if (run == null) {
+            return;
+        }
+        run.setProviderName(providerName);
+        run.setModelName(modelName);
+        run.setLatencyMs(latencyMs);
+        run.setUpdatedAt(LocalDateTime.now());
+        runMapper.updateById(run);
+    }
+
     @Override
     @Transactional
     public void syncGenerationTransition(Long generationRecordId, GenerationStatus target) {