feat(close): Add --suggest-next flag to show newly unblocked issues (GH#679)

When closing an issue, the new --suggest-next flag returns a list of
issues that became unblocked (ready to work on) as a result of the close.

This helps agents and users quickly identify what work is now available
after completing a blocker.

Example:
  $ bd close bd-5 --suggest-next
  ✓ Closed bd-5: Completed

  Newly unblocked:
    • bd-7 "Implement feature X" (P1)
    • bd-8 "Write tests for X" (P2)

Implementation:
- Added GetNewlyUnblockedByClose to storage interface
- Implemented efficient single-query for SQLite using blocked_issues_cache
- Added SuggestNext field to CloseArgs in RPC protocol
- Added CloseResult type for structured response
- CLI handles both daemon and direct modes

Thanks to @kraitsura for the detailed feature request and design.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

cmd/bd/formula.go

@@ -18,8 +18,8 @@ var formulaCmd = &cobra.Command{
 	Short: "Manage workflow formulas",
 	Long: `Manage workflow formulas - the source layer for molecule templates.
 
-Formulas are JSON files (.formula.json) that define workflows with composition rules.
-They are "cooked" into ephemeral protos which can then be poured or wisped.
+Formulas are YAML/JSON files that define workflows with composition rules.
+They are "cooked" into proto beads which can then be poured or wisped.
 
 The Rig → Cook → Run lifecycle:
   - Rig: Compose formulas (extends, compose)