Add plumbing integration and improve output format

- Add PLUMBING.md documentation for denote plumber integration
- Update DisplayNotes to use clickable format: denote:ID | title | tags
- Simplify plumbing rules to single pattern matching rule

PLUMBING.md

@@ -0,0 +1,64 @@
+# Plumbing Integration for Denote
+
+This document describes how to integrate the Denote command with the Plan 9 plumber to enable right-click opening of denote notes.
+
+## Overview
+
+The plumbing rules allow you to right-click on `denote:<identifier>` text in acme and have it automatically open the corresponding note.
+
+## Setup
+
+Add these rules to your `$HOME/lib/plumbing` file:
+
+```
+# declarations of ports without rules
+plumb to denote
+
+# Denote identifiers - open note by identifier
+type is text
+data matches 'denote:([0-9]+T[0-9]+)'
+plumb to denote
+plumb start Denote open $1
+```
+
+### Rule Placement
+
+- The port declaration (`plumb to denote`) should go with other port declarations near the top
+- The pattern matching rule should be placed **before** generic file matching rules to ensure it fires first
+
+## Reload Rules
+
+After editing `$HOME/lib/plumbing`, reload the rules:
+
+```rc
+cat $HOME/lib/plumbing | 9p write plumb/rules
+```
+
+## Usage
+
+Once configured, you can right-click (button 3) on any text matching the pattern:
+
+```
+denote:20251103T165653
+```
+
+This will execute `Denote open 20251103T165653` and open the note in acme.
+
+## Pattern Details
+
+The regex pattern `denote:([0-9]+T[0-9]+)` matches:
+- The literal text `denote:`
+- One or more digits
+- The letter `T`
+- One or more digits
+
+This matches the standard Denote identifier format: `YYYYMMddTHHmmss`
+
+## Troubleshooting
+
+If right-clicking doesn't work:
+
+1. Verify rules are loaded: `9p read plumb/rules | grep denote`
+2. Check the command exists: `which Denote`
+3. Test manually: `plumb "denote:20251103T165653"`
+4. Ensure the pattern uses `+` not `{n}` quantifiers (Plan 9 regex limitation)

cmd/Denote/main.go

@@ -4,6 +4,7 @@ import (
 	"flag"
 	"fmt"
 	"os"
+	"os/exec"
 	"path/filepath"
 	"regexp"
 	"strings"
@@ -272,6 +273,44 @@ func handleRenameReturnNote(args []string) *denote.Note {
 	return renamedNote
 }
 
+func handleOpen(dir string, args []string) {
+	if len(args) == 0 {
+		fmt.Fprintf(os.Stderr, "Usage: open <identifier>\n\nOpen a note by its identifier.\n\nExample:\n  open 20251016T091314\n")
+		os.Exit(0)
+	}
+	
+	identifier := args[0]
+	
+	// Search for note with this identifier
+	identFilter, err := denote.ParseFilter(fmt.Sprintf("date:%s", identifier))
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "error: invalid identifier: %v\n", err)
+		os.Exit(1)
+	}
+	
+	notes, err := denote.FindNotes(dir, []*denote.Filter{identFilter})
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "error searching for note: %v\n", err)
+		os.Exit(1)
+	}
+	
+	if len(notes) == 0 {
+		fmt.Fprintf(os.Stderr, "error: no note found with identifier %s\n", identifier)
+		os.Exit(1)
+	}
+	
+	if len(notes) > 1 {
+		fmt.Fprintf(os.Stderr, "warning: multiple notes found with identifier %s, opening first\n", identifier)
+	}
+	
+	// Open the file in acme using plumb
+	cmd := exec.Command("plumb", notes[0].Path)
+	if err := cmd.Run(); err != nil {
+		fmt.Fprintf(os.Stderr, "error opening file: %v\n", err)
+		os.Exit(1)
+	}
+}
+
 func main() {
 	dir := flag.String("dir", denote.DefaultDir(), "denote directory")
 	flag.Parse()
@@ -354,6 +393,7 @@ Usage:
   Denote + 'Title' [tags...]           Alias for new
   Denote rename /path ['Title'] [tags...]  Rename a note
   Denote r /path ['Title'] [tags...]   Alias for rename
+  Denote open <identifier>             Open note by identifier
   Denote ?                             Show this help
 
 Filters:
@@ -390,6 +430,12 @@ For 'rename' command help: Denote rename
 		return
 	}
 
+	// Check if this is an "open" command
+	if len(filterArgs) > 0 && filterArgs[0] == "open" {
+		handleOpen(*dir, filterArgs[1:])
+		return
+	}
+
 	var filters []*denote.Filter
 	sortType := denote.SortByID // Default sort
 

internal/denote/denote.go

@@ -233,11 +233,8 @@ func DisplayNotes(notes []*Note) error {
 			title = "(untitled)"
 		}
 		
-		buf.WriteString(title)
-		if len(n.Keywords) > 0 {
-			fmt.Fprintf(&buf, " (%s)", strings.Join(n.Keywords, ", "))
-		}
-		fmt.Fprintf(&buf, "\n%s\n\n", n.Path)
+		tags := strings.Join(n.Keywords, ", ")
+		fmt.Fprintf(&buf, "denote:%s | %s | %s\n", n.Identifier, title, tags)
 	}
 
 	w.Write("body", []byte(buf.String()))