chore: Bump version to 0.26.0

Release highlights:
- bd doctor --check-health for lightweight startup hook health checks
- --no-git-history flag to prevent spurious deletions
- gh2jsonl --id-mode hash for content-based ID generation
- Critical MCP protocol stdin fix (PR #400)
- Git worktree staleness fix (#399)
- Multi-part prefix support (#398)
- bd sync commit scope fix

Updated all component versions:
- bd CLI: 0.25.1 -> 0.26.0
- Plugin: 0.25.1 -> 0.26.0
- MCP server: 0.25.1 -> 0.26.0
- npm package: 0.25.1 -> 0.26.0

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

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

cmd/bd/info.go

@@ -287,6 +287,19 @@ type VersionChange struct {
 
 // versionChanges contains agent-actionable changes for recent versions
 var versionChanges = []VersionChange{
+	{
+		Version: "0.26.0",
+		Date:    "2025-11-27",
+		Changes: []string{
+			"bd doctor --check-health - Lightweight health checks for startup hooks (exit 0 on success)",
+			"--no-git-history flag - Prevent spurious deletions when git history is unreliable",
+			"gh2jsonl --id-mode hash - Hash-based ID generation for GitHub imports",
+			"MCP Protocol Fix (PR #400) - Subprocess stdin no longer breaks MCP JSON-RPC",
+			"Git Worktree Staleness Fix (#399) - Staleness check works after writes in worktrees",
+			"Multi-Part Prefix Support (#398) - Handles prefixes like 'my-app-123' correctly",
+			"bd sync Commit Scope Fixed - Only commits .beads/ files, not other staged files",
+		},
+	},
 	{
 		Version: "0.25.1",
 		Date:    "2025-11-25",