feat: import agents_and_robots platform as unibots (Matrix-out, unibus transport)

Reemplaza el scaffold del echobot por la plataforma completa de bots traida
desde ~/DataProyects/Github/agents_and_robots tras la operacion Matrix-out:
los bots ya no hablan por Matrix sino por el bus unibus (modelo todo-rooms +
E2E via shell/transportunibus sobre github.com/enmanuel/unibus/pkg/client).

- go.mod: replace de unibus -> ../unibus y de fn-registry -> ../../../.. (paths
  relativos reajustados a la nueva ubicacion dentro de fn_registry).
- app.md: bump a 0.2.0, descripcion + arquitectura + comandos + gotchas reales.
- modulo Go conservado como github.com/enmanuel/agents (sin reescribir imports).

agents_and_robots queda archivado como museo de la era Matrix.

cmd/launcher/sqlite.go

@@ -0,0 +1,37 @@
+package main
+
+import (
+	"context"
+	"database/sql"
+	"database/sql/driver"
+
+	moderncsqlite "modernc.org/sqlite"
+)
+
+func init() {
+	// mautrix dbutil opens sqlite as "sqlite3"; register the pure-Go driver
+	// under that name. We add a connection hook that sets WAL mode and a
+	// busy timeout on every connection to prevent SQLITE_BUSY crashes during
+	// concurrent writes (crypto store sync + memory store).
+	d := &moderncsqlite.Driver{}
+	d.RegisterConnectionHook(sqlitePragmaHook)
+	sql.Register("sqlite3", d)
+}
+
+// sqlitePragmaHook sets WAL journal mode and a 5-second busy timeout on
+// every new SQLite connection. This prevents SQLITE_BUSY errors when
+// multiple goroutines write concurrently (e.g. mautrix crypto sync +
+// memory/knowledge stores).
+func sqlitePragmaHook(conn moderncsqlite.ExecQuerierContext, _ string) error {
+	ctx := context.Background()
+	pragmas := []string{
+		"PRAGMA journal_mode=WAL",
+		"PRAGMA busy_timeout=5000",
+	}
+	for _, p := range pragmas {
+		if _, err := conn.ExecContext(ctx, p, []driver.NamedValue{}); err != nil {
+			return err
+		}
+	}
+	return nil
+}