fix: hyperguild brain write requires wing/hall, not legacy type/slug (#79)

Removes brain_write legacy domain/type/knowledge-path params (ADR-0012) and migrates the previously-missed cmd/hyperguild CLI caller (hyperguild brain write) from <type> <slug> to <wing> <hall> <slug>, fixing a 100%% regression the first review round caught. Adds TestWrite_CLIPayloadRoundTrips exercising the real Handler.Write over HTTP to pin the wire contract.

Closes #79.

Co-authored-by: Mathias <mthbqv@gmail.com>

cmd/hyperguild/http.go

@@ -84,16 +84,17 @@ type WriteResult struct {
 	Path string `json:"path"`
 }
 
-func (c *brainClient) Write(ctx context.Context, kind, slug string, content io.Reader) (*WriteResult, error) {
+func (c *brainClient) Write(ctx context.Context, wing, hall, filename string, content io.Reader) (*WriteResult, error) {
 	body, err := io.ReadAll(content)
 	if err != nil {
 		return nil, fmt.Errorf("read content: %w", err)
 	}
 	payload, err := json.Marshal(struct {
-		Type    string `json:"type"`
-		Slug    string `json:"slug"`
-		Content string `json:"content"`
-	}{Type: kind, Slug: slug, Content: string(body)})
+		Wing     string `json:"wing"`
+		Hall     string `json:"hall"`
+		Filename string `json:"filename"`
+		Content  string `json:"content"`
+	}{Wing: wing, Hall: hall, Filename: filename, Content: string(body)})
 	if err != nil {
 		return nil, fmt.Errorf("marshal payload: %w", err)
 	}