Add the plugin's SessionStart hook so a session learns its own id (issue 1744)

A session is never told its session id by any tool, only by a hook's
stdin, so it cannot name itself to claude_code_wait. The plugin's
SessionStart hook (claude-code session-start <waits-dir>) prints the id
and how to give it, plus the session's still-open waits after a /clear,
reading the waits file claude_code_wait mirrors directly rather than
calling back into this module. Carries the Stop hook's command and the
GuardFiles.WaitsDir plumbing MarketplaceWith needs for both (issue 1743
wires the Stop hook's dispatch next).

modules/claude-code/cmd/claude-code/config.go

@@ -476,10 +476,13 @@ type PluginFile struct {
 // what it is given. Outside hooks/, so no registered hook's name can be it.
 const GuardDir = "guard"
 
-// GuardFiles are the guard as the plugin carries it: the binary to copy and the data it judges with.
+// GuardFiles are the guard as the plugin carries it: the binary to copy, what it judges with, and — the same
+// binary again — the waits directory the SessionStart and Stop hooks are given (novox/hq ADR 0489, issues
+// 1744, 1743). Empty WaitsDir places no such hook.
 type GuardFiles struct {
-	Exe  string
-	Data GuardData
+	Exe      string
+	Data     GuardData
+	WaitsDir string
 }
 
 // GuardMatcher is what the guard is asked about: every tool. Its own rules judge the shell and the agent's file
@@ -495,6 +498,20 @@ func GuardCommand() string {
 	return `"` + filepath.Join(dir, "guard") + `" guard "` + filepath.Join(dir, "guard.json") + `"`
 }
 
+// SessionStartCommand is the plugin's SessionStart hook: the guard's own binary, told the session's open
+// waits live under waitsDir (novox/hq ADR 0489 §3, issue 1744).
+func SessionStartCommand(waitsDir string) string {
+	dir := filepath.Join(ManagedDir, MarketplaceDir, "plugins", Plugin, GuardDir)
+	return `"` + filepath.Join(dir, "guard") + `" session-start "` + waitsDir + `"`
+}
+
+// StopCommand is the plugin's Stop hook: the guard's own binary, refusing to end the turn while a wait under
+// waitsDir is open and unwatched, or past its bound and untold (novox/hq ADR 0489 §3-§6, issue 1743).
+func StopCommand(waitsDir string) string {
+	dir := filepath.Join(ManagedDir, MarketplaceDir, "plugins", Plugin, GuardDir)
+	return `"` + filepath.Join(dir, "guard") + `" stop "` + waitsDir + `"`
+}
+
 // Marketplace is the marketplace directory's whole content, by path inside it. A node item of a name laid
 // over a mesh item of the same kind and name: the node's wins.
 func Marketplace(c Config) map[string]PluginFile { return MarketplaceWith(c, nil) }
@@ -533,6 +550,14 @@ func MarketplaceWith(c Config, guard *GuardFiles) map[string]PluginFile {
 		out[root+GuardDir+"/guard.json"] = PluginFile{Content: jsonFile(guard.Data)}
 		hooks["PreToolUse"] = append(hooks["PreToolUse"], map[string]any{"matcher": GuardMatcher,
 			"hooks": []any{map[string]any{"type": "command", "command": GuardCommand(), "timeout": 15}}})
+		if guard.WaitsDir != "" {
+			// A session's wait list (novox/hq ADR 0489): the SessionStart hook names the session's id and its open
+			// waits (issue 1744); the Stop hook keeps the turn open while one is unwatched or untold (issue 1743).
+			hooks["SessionStart"] = append(hooks["SessionStart"], map[string]any{"matcher": "startup|resume|clear|compact",
+				"hooks": []any{map[string]any{"type": "command", "command": SessionStartCommand(guard.WaitsDir), "timeout": 10}}})
+			hooks["Stop"] = append(hooks["Stop"], map[string]any{
+				"hooks": []any{map[string]any{"type": "command", "command": StopCommand(guard.WaitsDir), "timeout": 5}}})
+		}
 	}
 	for _, k := range keys {
 		it := chosen[k]