Document request-scoped MySQL cleanup

site/doc/pages/mysql_connect.txt

@@ -15,6 +15,8 @@ Establishes a connection to a MySQL server and returns a pointer to the connecti
 
 This connection handle is then used with helpers such as `mysql_query()`, `mysql_error()`, and `mysql_disconnect()`.
 
+MySQL handles are request-scoped framework resources. If a request exits without calling `mysql_disconnect()`, UCE closes any remaining MySQL handles during request cleanup. Call `mysql_disconnect()` when you want to close early, but never store a `MySQL*` in globals, sessions, or other state that can outlive the current request.
+
 :example
 MySQL* db = mysql_connect();
 print(db != 0 ? "connected to MySQL" : "no MySQL server reachable with these credentials", "\n");

site/doc/pages/mysql_disconnect.txt

@@ -10,7 +10,7 @@ m : pointer to an existing MySQL connection struct
 :content
 Closes an existing connection to a MySQL server.
 
-Call this when you are done using a `MySQL*` connection handle.
+Call this when you want to release a `MySQL*` connection handle before the request ends. UCE also closes any remaining MySQL handles automatically during request cleanup, including handles skipped by exceptions or fatal request recovery. A `MySQL*` is only valid inside the request that opened it; do not cache it across requests.
 
 :example
 MySQL* db = mysql_connect();

src/lib/mysql-connector.cpp

@@ -3,6 +3,10 @@
 #include <stdlib.h>
 #include "mysql-connector.h"
 
+// MySQL handles are request-scoped framework resources. User code may call
+// mysql_disconnect() to close early, but leaked/exception-skipped handles are
+// still closed by cleanup_mysql_connections() at request end. Handles must not
+// be cached across requests or stored in globals/sessions.
 static void mysql_register_request_connection(MySQL* db)
 {
 	if(!context || !db)

src/lib/mysql-connector.h

@@ -33,8 +33,10 @@ struct MySQL {
 	DValue query(String q, StringMap params);
 	DValue get_pending_result();
 
-	// Unregisters from the request's connection tracking, so stack-allocated
+	// Unregisters from request connection tracking, so stack-allocated instances
-	// instances cannot leave dangling pointers behind for request cleanup.
+	// cannot leave dangling pointers behind for request cleanup. Heap handles
+	// returned by mysql_connect() are also request-owned and auto-closed at the
+	// end of the request if user code does not call mysql_disconnect() first.
 	~MySQL() { disconnect(); }
 
 };

src/wasm/worker.cpp

@@ -799,7 +799,9 @@ public:
 
 #ifdef UCE_WASM_HOST_CONNECTORS
 	// Host-owned resource handle table (§3.1): connections opened by the guest
-	// live here and are closed when the workspace drops at request end.
+	// live here and are closed when the workspace drops at request end. This is
+	// the wasm-side enforcement of request-scoped DB lifecycle; app code should
+	// never cache these opaque handles across requests.
 	std::vector<SQLite*> sqlite_handles;
 	std::vector<MySQL*> mysql_handles;
 #endif