feat(go): durable transaction engine and Kiro IDE 1.0 adapter

Split the monolithic transaction into focused modules: append-only
crash-recoverable journal under ~/.elydora/transactions with owner
tokens and per-transaction namespaces, staged atomic publication
(stage .pending, fsync, rename, fsync), platform-specific atomic
replacement (MoveFileEx, renameat2, renamex_np), private-directory
hardening per OS, lock-guarded recovery, and workspace cleanup that
removes only transaction-created empty directories.

Add the Kiro IDE 1.0 plugin: strict v1 hook schema with one enabled
PreToolUse guard and PostToolUse audit pair bound to the active
workspace, agent-to-workspace identity binding in runtime config, and
exact migration of the legacy elydora-audit.kiro.hook contract.

Gates: go test ./... and -race pass, go vet clean, govulncheck reports
zero reachable vulnerabilities, git diff --check clean.

go.mod

@@ -6,7 +6,6 @@ require github.com/pelletier/go-toml/v2 v2.4.3
 
 require (
 	github.com/tailscale/hujson v0.0.0-20221223112325-20486734a56a
+	golang.org/x/sys v0.30.0
 	golang.org/x/term v0.29.0
 )
-
-require golang.org/x/sys v0.30.0 // indirect