convention: fiber titles are 2-3 word DAG node labels

- hook: add title convention to Core Rules in both session and minimal output
- add: soft warning to stderr when title exceeds 5 words

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: cailmdaley

cmd/add.go

@@ -2,6 +2,8 @@ package cmd
 
 import (
 	"fmt"
+	"os"
+	"strings"
 	"time"
 
 	"github.com/cailmdaley/felt/internal/felt"
@@ -91,6 +93,12 @@ var addCmd = &cobra.Command{
 			f.Outcome = addOutcome
 		}
 
+		// Warn if title is long — titles render as DAG node labels (2-3 words ideal)
+		if len(strings.Fields(f.Title)) > 5 {
+			fmt.Fprintf(os.Stderr, "warning: title %q is long (%d words); titles render as DAG node labels — keep to 2-3 words, put detail in body/outcome\n",
+				f.Title, len(strings.Fields(f.Title)))
+		}
+
 		if err := storage.Write(f); err != nil {
 			return err
 		}

cmd/hook.go

@@ -68,6 +68,7 @@ func minimalOutput() string {
 - Track **decisions** — what was decided, why, and how decisions depend on each other
 - Outcome (` + "`-o`" + `) is the documentation: capture the conclusion, the reasoning, what was learned
 - **Leave a wake** — file as you go; the DAG forms after your path
+- **Titles are DAG node labels: 2-3 words.** The body and outcome carry full content.
 `
 }
 
@@ -151,6 +152,7 @@ func formatSessionOutput(felts []*felt.Felt, g *felt.Graph) string {
 	sb.WriteString("- Track **decisions** — what was decided, why, and how decisions depend on each other\n")
 	sb.WriteString("- Outcome (`-o`) is the documentation: capture the conclusion, the reasoning, what was learned\n")
 	sb.WriteString("- **Leave a wake** — file as you go; the DAG forms after your path\n")
+	sb.WriteString("- **Titles are DAG node labels: 2-3 words.** The body and outcome carry full content.\n")
 
 	return sb.String()
 }