fix(workflow_run_trigger): 204 dispatch is success; resolve run via listing (#41)

Gitea's workflow_dispatch endpoint returns 204 No Content with no Location
header. DispatchWorkflow required that header, so every successful dispatch
errored with "missing Location header" and never yielded a run ID — making
the tool unusable for CAD dispatch.

- DispatchWorkflow now returns error-only; 204 = success, no Location needed.
  Body already carried ref+inputs; kept and covered by test.
- Tool snapshots the newest existing workflow_dispatch run before dispatch,
  then polls ListWorkflowRuns after and returns the newest run with ID above
  that baseline (avoids returning a stale prior run). Falls back to an honest
  "dispatched, run not yet registered" result rather than failing.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

internal/gitea/workflows.go

@@ -6,7 +6,6 @@ import (
 	"fmt"
 	"net/url"
 	"strconv"
-	"strings"
 )
 
 // DispatchWorkflowArgs is the request body for a workflow_dispatch trigger.
@@ -15,42 +14,26 @@ type DispatchWorkflowArgs struct {
 	Inputs map[string]any `json:"inputs,omitempty"`
 }
 
-// WorkflowRunTrigger holds the run ID extracted from the Location header.
-type WorkflowRunTrigger struct {
-	RunID int64
-}
-
-// DispatchWorkflow triggers a workflow_dispatch event and returns the new run ID.
-func (c *Client) DispatchWorkflow(ctx context.Context, owner, repo, workflow string, args DispatchWorkflowArgs) (*WorkflowRunTrigger, error) {
+// DispatchWorkflow triggers a workflow_dispatch event. Gitea returns 204 No
+// Content with NO Location header, so the response carries no run ID — callers
+// resolve the new run separately via ListWorkflowRuns. Returns nil on success.
+func (c *Client) DispatchWorkflow(ctx context.Context, owner, repo, workflow string, args DispatchWorkflowArgs) error {
 	p := fmt.Sprintf("/api/v1/repos/%s/%s/actions/workflows/%s/dispatches", owner, repo, workflow)
 	payload, err := json.Marshal(args)
 	if err != nil {
-		return nil, err
+		return err
 	}
 	resp, err := c.doRaw(ctx, "POST", p, payload)
 	if err != nil {
-		return nil, err
+		return err
 	}
 	if resp.Status != 204 {
 		if mapErr := MapStatus(resp.Status, resp.Body); mapErr != nil {
-			return nil, mapErr
+			return mapErr
 		}
-		return nil, fmt.Errorf("unexpected status %d", resp.Status)
+		return fmt.Errorf("unexpected status %d", resp.Status)
 	}
-	location := resp.Headers.Get("Location")
-	if location == "" {
-		return nil, fmt.Errorf("missing Location header in dispatch response")
-	}
-	// Location is e.g. "/api/v1/repos/o/r/actions/runs/123" — take the last segment.
-	parts := strings.Split(strings.TrimRight(location, "/"), "/")
-	if len(parts) == 0 {
-		return nil, fmt.Errorf("malformed Location: %s", location)
-	}
-	runID, err := strconv.ParseInt(parts[len(parts)-1], 10, 64)
-	if err != nil {
-		return nil, fmt.Errorf("parse run id from %q: %w", location, err)
-	}
-	return &WorkflowRunTrigger{RunID: runID}, nil
+	return nil
 }
 
 // WorkflowRun represents a Gitea Actions run.