feat: add --notes flag to bd create command (GH#830)

Add --notes flag to bd create command, enabling agents to set notes
during issue creation instead of requiring a separate update command.

Motivation: AI agents repeatedly tried to use --notes with bd create.
Context is fresh at creation time - forcing a two-step process means
context loss or workflow interruption.

Changes:
- cmd/bd/flags.go: Added --notes flag to common issue flags
- cmd/bd/create.go: Read and pass notes in both RPC and direct modes
- cmd/bd/update.go: Removed duplicate --notes flag definition
- internal/rpc/protocol.go: Added Notes field to CreateArgs
- internal/rpc/server_issues_epics.go: Process Notes in handleCreate
- cmd/bd/create_notes_test.go: Comprehensive test coverage
- website/docs/cli-reference/issues.md: Documentation

Also adds gitignore entries for Augment AI and .beads/redirect.

Co-authored-by: Leon Letto <lettol@vmware.com>

internal/rpc/protocol.go

@@ -82,6 +82,7 @@ type CreateArgs struct {
 	Priority           int      `json:"priority"`
 	Design             string   `json:"design,omitempty"`
 	AcceptanceCriteria string   `json:"acceptance_criteria,omitempty"`
+	Notes              string   `json:"notes,omitempty"`
 	Assignee           string   `json:"assignee,omitempty"`
 	ExternalRef        string   `json:"external_ref,omitempty"`  // Link to external issue trackers
 	EstimatedMinutes   *int     `json:"estimated_minutes,omitempty"` // Time estimate in minutes